U.S. patent application number 16/385783 was filed with the patent office on 2019-08-08 for electrochromic device including a means for preventing ion migration and a process of forming the same.
The applicant listed for this patent is SAGE ELECTROCHROMICS, INC.. Invention is credited to Joao ABREU, Sophie BROSSARD, Jean-Christophe GIRON, Charles LEYDER.
Application Number | 20190243205 16/385783 |
Document ID | / |
Family ID | 60243465 |
Filed Date | 2019-08-08 |
United States Patent
Application |
20190243205 |
Kind Code |
A1 |
BROSSARD; Sophie ; et
al. |
August 8, 2019 |
ELECTROCHROMIC DEVICE INCLUDING A MEANS FOR PREVENTING ION
MIGRATION AND A PROCESS OF FORMING THE SAME
Abstract
An electrochromic device can include a substrate; an
electrochromic layer or a counter electrode layer over the
substrate and including a mobile ion; a first transparent
conductive layer over the substrate and including Ag. In one
embodiment, the electrochromic device can include a barrier layer
disposed between first transparent conductive layer and the
electrochromic or counter electrode layer. In another embodiment,
the electrochromic device can include means for preventing (1) the
mobile ion from migrating into the first transparent conductive
layer, (2) Ag from migrating into the electrochromic layer or
counter electrode layer, or both (1) and (2). A process of forming
an electrochromic device can include forming an electrochromic
layer or a counter electrode layer over a substrate; forming a
barrier layer; and forming a first transparent conductive layer
over the substrate.
Inventors: |
BROSSARD; Sophie; (Paris,
FR) ; GIRON; Jean-Christophe; (Edina, MN) ;
LEYDER; Charles; (Cambridge, MA) ; ABREU; Joao;
(Paris, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAGE ELECTROCHROMICS, INC. |
Faribault |
MN |
US |
|
|
Family ID: |
60243465 |
Appl. No.: |
16/385783 |
Filed: |
April 16, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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15586897 |
May 4, 2017 |
10303032 |
|
|
16385783 |
|
|
|
|
62333386 |
May 9, 2016 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02F 2001/1555 20130101;
G02F 1/155 20130101; C03C 17/3618 20130101; C03C 17/3652 20130101;
C03C 2218/326 20130101; C03C 2218/322 20130101; C03C 17/366
20130101; G02F 1/1533 20130101; C03C 17/3681 20130101; C03C 17/36
20130101; C03C 17/3644 20130101; G02F 2001/1536 20130101 |
International
Class: |
G02F 1/153 20060101
G02F001/153; C03C 17/36 20060101 C03C017/36; G02F 1/155 20060101
G02F001/155 |
Claims
1. An electrochromic device comprising: a substrate; an
electrochromic layer or a counter electrode layer over the
substrate, wherein the electrochromic or counter electrode layer
includes a mobile ion; a first transparent conductive layer over
the substrate and including Ag; and a barrier layer disposed
between first transparent conductive layer and the electrochromic
or counter electrode layer, wherein the barrier layer prevents the
mobile ion from migrating into the first transparent conductive
layer and Ag from migrating into the electrochromic layer or
counter electrode layer.
2. The electrochromic device of claim 1, wherein the barrier layer
is conformal.
3. The electrochromic device of claim 2, wherein the barrier layer
has a thickness of in a range of 5 nm to 200 nm.
4. The electrochromic device of claim 1, wherein the barrier layer
includes a metal nitride.
5. The electrochromic device of claim 4, wherein the barrier layer
includes AN.
6. The electrochromic device of claim 4, wherein the barrier layer
includes TiN.
7. The electrochromic device of claim 1, wherein the barrier layer
is spaced apart from the Ag within the first transparent conductive
layer.
8. The electrochromic device of claim 7, further comprising a first
transparent conductive oxide between the Ag and the barrier
layer.
9. An electrochromic device comprising: a substrate; an
electrochromic stack comprising: an electrochromic layer or a
counter electrode layer over the substrate, wherein the
electrochromic or counter electrode layer includes a mobile ion; a
first transparent conductive layer over the substrate and including
Ag; and a barrier layer disposed between first transparent
conductive layer and the electrochromic or counter electrode layer,
wherein the barrier layer prevents the mobile ion from migrating
into the first transparent conductive layer and Ag from migrating
into the electrochromic layer or counter electrode layer; and a
second transparent conductive layer.
10. The electrochromic device of claim 9, wherein the first
transparent conductive layer is coupled to one of the
electrochromic layer and the counter electrode layer, and the
second transparent conductive layer is coupled to the other of the
electrochromic layer and the counter electrode layer.
11. A process of forming an electrochromic device comprising:
providing a substrate; forming an electrochromic layer or a counter
electrode layer over the substrate, wherein after forming the
electrochromic or counter electrode layer, the electrochromic or
counter electrode layer includes a mobile ion; forming a barrier
layer over the substrate; and forming a first transparent
conductive layer over the substrate and including Ag, wherein
forming the barrier layer is formed between forming the
electrochromic or counter electrode layer and forming the first
transparent conductive layer, and wherein forming the barrier layer
is performed using a metal-silicon compound.
12. The process of claim 11, wherein forming the barrier layer is
performed using atomic layer deposition.
13. The process of claim 12, wherein the barrier layer includes
titanium silicon nitride, a tantalum silicon nitride, or a tungsten
silicon nitride.
14. The process of claim 12, wherein the barrier layer has a
thickness of in a range of 5 nm to 200 nm.
15. The process of claim 11, further comprising forming a second
transparent oxide along a side of the Ag that is opposite the
barrier layer.
16. The process of claim 11, wherein forming the barrier layer is
performed using H.sub.2O, H.sub.2O.sub.2, O.sub.2, or O.sub.3, or
any combination thereof.
17. The process of claim 16, wherein the barrier layer includes a
metal oxide.
18. The process of claim 17, wherein the barrier layer includes
Al.sub.2O.sub.3 or TiO.sub.2.
19. The process of claim 11, wherein the barrier layer is spaced
apart from the Ag within the first transparent conductive
layer.
20. The process of claim 19, further comprising a first transparent
conductive oxide between the Ag and the barrier layer.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of and claims priority
under 35 U.S.C. 120 to U.S. patent application Ser. No. 15/586,897,
filed May 4, 2017, entitled "Electrochromic Device Including a
Means For Preventing Ion Migration and a Process of Forming the
Same," naming as inventors Sophie Brossard et al., which claims
priority under 35 U.S.C. .sctn. 119(e) to U.S. Provisional Patent
Application No. 62/333,386, filed May 9, 2016, entitled
"Electrochromic Device Including a Means For Preventing Ion
Migration and a Process of Forming the Same," naming as inventors
Sophie Brossard et al., which applications are assigned to the
current assignee hereof and are incorporated by reference herein in
their entireties.
FIELD OF THE DISCLOSURE
[0002] The present disclosure is directed to electrochromic
devices, and more specifically to electrochromic devices including
means for preventing ion migration and processes of forming the
same.
BACKGROUND
[0003] An electrochromic device helps to block the transmission of
visible light and keep a room of a building or passenger
compartment of a vehicle from becoming too warm. A low-emissivity
film can be used to reflect solar heat, which can also help keep a
room of a building or passenger compartment of a vehicle from
becoming too warm. The low-emissivity film can include Ag and is
spaced apart and not part of the electrochromic device. Further
improvement of window designs is desired.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Embodiments are illustrated by way of example and are not
limited in the accompanying figures.
[0005] FIG. 1 includes a flow diagram for a process of forming an
electrochromic device in accordance with an embodiment as described
herein.
[0006] FIG. 2 includes an illustration of a cross-sectional view of
a workpiece including a substrate and a partially formed
electrochromic stack.
[0007] FIG. 3 includes an illustration of a cross-sectional view of
the workpiece of FIG. 2 after forming a barrier layer.
[0008] FIG. 4 includes an illustration of a cross-sectional view of
the workpiece of FIG. 3 after forming a transparent conductive
layer.
[0009] FIG. 5 includes an illustration of a cross-sectional view of
the workpiece of FIG. 4 after patterning the electrochromic
stack.
[0010] FIG. 6 includes an illustration of a cross-sectional view of
the workpiece of FIG. 5 after forming bus bars.
[0011] FIG. 7 includes an illustration of a cross-sectional view of
the workpiece of FIG. 6 after forming a substantially completed
electrochromic device.
[0012] FIG. 8 includes illustration of a cross-sectional view of an
insulating glass unit that includes the electrochromic device of
FIG. 7.
[0013] Skilled artisans appreciate that elements in the figures are
illustrated for simplicity and clarity and have not necessarily
been drawn to scale. For example, the dimensions of some of the
elements in the figures may be exaggerated relative to other
elements to help to improve understanding of embodiments of the
invention.
DETAILED DESCRIPTION
[0014] The following description in combination with the figures is
provided to assist in understanding the teachings disclosed herein.
The following discussion will focus on specific implementations and
embodiments of the teachings. This focus is provided to assist in
describing the teachings and should not be interpreted as a
limitation on the scope or applicability of the teachings.
[0015] In this specification, refractive indices are measured at
550 nm.
[0016] As used herein, the terms "comprises," "comprising,"
"includes," "including," "has," "having," or any other variation
thereof, are intended to cover a non-exclusive inclusion. For
example, a process, method, article, or apparatus that comprises a
list of features is not necessarily limited only to those features
but may include other features not expressly listed or inherent to
such process, method, article, or apparatus. Further, unless
expressly stated to the contrary, "or" refers to an inclusive-or
and not to an exclusive-or. For example, a condition A or B is
satisfied by any one of the following: A is true (or present) and B
is false (or not present), A is false (or not present) and B is
true (or present), and both A and B are true (or present).
[0017] The use of "a" or "an" is employed to describe elements and
components described herein. This is done merely for convenience
and to give a general sense of the scope of the invention. This
description should be read to include one or at least one and the
singular also includes the plural, or vice versa, unless it is
clear that it is meant otherwise.
[0018] The use of the word "about", "approximately", or
"substantially" is intended to mean that a value of a parameter is
close to a stated value or position. However, minor differences may
prevent the values or positions from being exactly as stated. Thus,
differences of up to ten percent (10%) for the value are reasonable
differences from the ideal goal of exactly as described.
[0019] Unless otherwise defined, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this invention belongs. The
materials, methods, and examples are illustrative only and not
intended to be limiting. To the extent not described herein, many
details regarding specific materials and processing acts are
conventional and may be found in textbooks and other sources within
the glass, vapor deposition, and electrochromic arts.
[0020] In an aspect, an electrochromic device can include a
substrate; an electrochromic layer or a counter electrode layer
over the substrate, wherein the electrochromic or counter electrode
layer includes a mobile ion; a first transparent conductive layer
over the substrate and including Ag; and a barrier layer disposed
between first transparent conductive layer and the electrochromic
or counter electrode layer. In another aspect, an electrochromic
device can include a substrate; an electrochromic layer or a
counter electrode layer over the substrate, wherein the
electrochromic or counter electrode layer includes a mobile ion; a
first transparent conductive layer over the substrate and including
Ag; and means for preventing (1) the mobile ion from migrating into
the first transparent conductive layer, (2) Ag from migrating into
the electrochromic layer or counter electrode layer, or both (1)
and (2).
[0021] In a further aspect, a process of forming an electrochromic
device can include providing a substrate; forming an electrochromic
layer or a counter electrode layer over the substrate, wherein
after forming the electrochromic or counter electrode layer, the
electrochromic or counter electrode layer includes a mobile ion.
The process can further include forming a barrier layer and forming
a first transparent conductive layer over the substrate and
including Ag, wherein forming the barrier layer is formed between
forming the electrochromic or counter electrode layer and forming
the first transparent conductive layer.
[0022] The incorporation of Ag into a transparent conductive layer
of the electrochromic device allows for a low emissivity
electrochromic stack, and thus, a separate low emissivity film
spaced apart from the electrochromic stack is not needed. However,
the inventors discovered that when Ag is present in the transparent
conductive layer, the electrochromic device may operate properly
once, operate for less than a few hours, or may not operate
properly at all. Although not to be bound by theory, mobile ions,
such as Li+, may be migrating into a transparent conductive layer.
Alternatively, Ag may be migrating into an electrochromic layer or
a counter electrode layer and competing or interfering with the
mobile ions. The barrier layer or means for preventing migration of
mobile ions or Ag allows for the integration of a low emissivity
film within a layer of an electrochromic stack and still maintain
acceptable performance of an electrochromic device.
[0023] The embodiments as illustrated in the figures and described
below help in understanding particular applications for
implementing the concepts as described herein. The embodiments are
exemplary and not intended to limit the scope of the appended
claims.
[0024] FIG. 1 includes a process flow of forming an electrochromic
device in accordance with an embodiment. The process can include
forming a partially fabricated electrochromic stack over a
substrate, at block 102. FIG. 2 includes an illustration of a
cross-section view of a partially fabricated electrochromic device
after forming an electrochromic stack. The electrochromic device
can include a transparent substrate 200 that includes a glass
substrate, a sapphire substrate, an aluminum oxynitride (AlON)
substrate, a spinel substrate, or a transparent polymer. In a
particular embodiment, the transparent substrate 200 can include
ultra-thin glass that is a mineral glass having a thickness in a
range of 50 microns to 300 microns. The transparent polymer can
include a polyacrylate, a polyester, a polycarbonate, a
polysiloxane, a polyether, a polyvinyl compound, another suitable
class of transparent polymer, or a mixture thereof. In another
embodiment, the transparent substrate 200 can be a laminate
including layers of the materials that make up the previously
described transparent substrates. In another embodiment, the
laminate can include a solar control layer that reflects
ultraviolet radiation or a low emissivity material. The substrate
200 may or may not be flexible.
[0025] In an embodiment, the transparent substrate 200 can be a
glass substrate that can be a mineral glass including SiO.sub.2 and
one or more other oxides. Such other oxides can include
Al.sub.2O.sub.3, an oxide of an alkali metal, an oxide of an
alkaline earth metal, B.sub.2O.sub.3, ZrO.sub.2, P.sub.2O.sub.5,
ZnO, SnO.sub.2, SO.sub.3, As.sub.2O.sub.2, or Sb.sub.2O.sub.3. The
transparent substrate 200 may include a colorant, such as oxides of
iron, vanadium, titanium, chromium, manganese, cobalt, nickel,
copper, cerium, neodymium, praseodymium, or erbium, or a metal
colloid, such as copper, silver, or gold, or those in an elementary
or ionic form, such as selenium or sulfur.
[0026] In an embodiment in which the transparent substrate 200 is a
glass substrate, the glass substrate is at least 50 wt. %
SiO.sub.2. In an embodiment, the SiO.sub.2 content is in a range of
50 wt. % to 85 wt. %. Al.sub.2O.sub.3 may help with scratch
resistance, for example, when the major surface is along an exposed
surface of the laminate being formed. When present, Al.sub.2O.sub.3
content can be in a range of 1 wt. % to 20 wt. %. B.sub.2O.sub.3
can be usefully used to reduce both the viscosity of the glass and
its thermal expansion coefficient. The B.sub.2O.sub.3 content may
be no greater than 20 wt. %, and in a particular embodiment, less
than 15 wt. %. Alkaline earth metals include magnesium, calcium,
strontium, and barium. The oxides of an alkaline earth metal are
useful for reducing the viscosity of the glass and facilitating
fusion, without heavily penalizing the expansion coefficient.
Calcium and magnesium have a relatively low impact on the density
of the glass as compared to some of the other oxides. The total
content of alkaline metal oxide may be no greater than 25 wt. %, 20
wt. %, or 15 wt. %. Oxides of an alkali metal can reduce viscosity
of the glass substrate and its propensity to devitrify. The total
content of alkali metal oxides may be at most than 8 wt. %, 5 wt.
%, or 1 wt. %. In some applications, the glass substrate is desired
to be clear, and thus, the content of colorants is low. In a
particular embodiment, the iron content is less than 200 ppm.
[0027] The glass substrate can include heat-strengthened glass,
tempered glass, partially heat-strengthened or tempered glass, or
annealed glass. "Heat-strengthened glass" and "tempered glass", as
those terms are known in the art, are both types of glass that have
been heat treated to induce surface compression and to otherwise
strengthen the glass. Heat-treated glasses are classified as either
fully tempered or heat-strengthened. In an embodiment, the glass
substrate is tempered glass and has a surface compression of about
69 MPa or more and an edge compression of about 67 MPa or more. In
another embodiment, the transparent substrate is heat-strengthened
and has a surface compression in a range of 24 MPa to 69 MPa and an
edge compression between 38 MPa and 67 MPa. The term "annealed
glass" means glass produced without internal strain imparted by
heat treatment and subsequent rapid cooling. Thus annealed glass
only excludes heat-strengthened glass or tempered glass. The glass
substrate can be laser cut.
[0028] A transparent conductive layer 202 overlies the transparent
substrate 200. The transparent conductive layer 202 can include
doped metal oxide. The doped metal oxide can include a zinc oxide
or a tin oxide, either of which may be doped with a Group 13
element, such as Al, Ga, or In. Indium tin oxide (ITO) and aluminum
zinc oxide (AZO) are exemplary, non-limiting materials that can be
used. In another embodiment, the transparent conductive layer 202
can be a polyaniline, polypyrrole, a polythiophene (e.g.,
poly(3,4-ethylenedioxythiophene) (PDOT)), another suitable
conductive organic polymer, or any combination thereof. If needed
or desired, the organic compound may be sulfonated. As illustrated
in FIG. 2, the transparent conductive layer 202 has a cut to allow
a subsequently-formed bus bar to contact the right-hand portion of
the transparent conductive layer 202 without electrically shorting
such bus bar to the left-hand portion of the transparent conductive
layer 202. The transparent conductive layer 202 has a thickness in
a range of 150 nm to 600 nm.
[0029] An electrode layer 204, an electrolyte layer 206, and
another electrode layer 208 overlie the transparent conductive
layer 202 and the transparent substrate 200. The electrode layer
204 can be the electrochromic (EC) layer or the counter electrode
(CE) layer, and the electrode layer 208 is the other of the CE
layer or the EC layer.
[0030] The EC layer can have a variable transmission of visible
light and near infrared radiation (e.g., electromagnetic radiation
having wavelengths in a range of 700 nm to 2500 nm) depending on
the biasing conditions. For example, in the absence of an
electrical field, the electrochromic device is in a high
transmission ("bleached") state, and in the presence of an
electrical field, mobile ions, such as Li.sup.+, Na.sup.+, or
H.sup.+, can migrate from the CE layer, through the electrolyte
layer to the EC layer and reduce the transmission of visible light
and near infrared radiation through the electrochromic device. The
lower transmission state may also be referred to as a tinted or
colored state. The EC layer can include an oxide of a transition
metal, such as iridium, rhodium, ruthenium, tungsten, manganese,
cobalt, or the like. In a particular embodiment, the EC layer
includes WO.sub.3. As initially formed, the EC layer may not
include any significant amount of the mobile ions that cause the EC
layer to have a reduced transmission. In another embodiment, the EC
layer may include at least some mobile ions, however, the
electrochromic device may be reverse biased to move the mobile ions
from the EC layer, through the electrolyte layer 206 to the CE
layer. In an embodiment, the thickness of the EC layer as deposited
is in a range 80 nm to 600 nm.
[0031] The CE layer can provide a principal source of mobile ions.
Furthermore, the CE layer remains substantially transparent to
visible light when the electrochromic device is in its high
transmission state and its low transmission state. The CE layer can
include an oxide of transition metal element. In embodiment, the CE
layer can include an oxide of nickel. The nickel may be in its
divalent state (Ni.sup.2+), its trivalent state (Ni.sup.3+), or a
combination thereof. The CE layer can include an oxide of a
transition metal element, such as such as iridium, rhodium,
ruthenium, tungsten, manganese, cobalt, or the like. The CE layer
can also provide mobile ions that can pass through the electrolyte
layer 206. The mobile ions may be incorporated into the CE layer as
it is formed. In a finished device, the CE layer may be represented
by a chemical formula of:
A.sub.xNi.sup.2+.sub.(1-y)Ni.sup.3+.sub.yM.sub.zO.sub.a,
[0032] where:
[0033] A is an element that produces a mobile ion, such as Li, Na,
or H;
[0034] M is a metal; and
[0035] 0.ltoreq.x.ltoreq.10, 0.ltoreq.y.ltoreq.1,
0.ltoreq.z.ltoreq.10, and
(0.5x+1+0.5y+z).ltoreq.a.ltoreq.(0.5x+1+0.5y+3.5z).
[0036] In a particular non-limiting embodiment, A is Li, M is W,
and, in a finished device, the CE layer may be represented by a
chemical formula of:
Li.sub.xNi.sup.2+.sub.(1-y)Ni.sup.3+.sub.yW.sub.zO.sub.(1+0.5x+0.5y+3z),
[0037] where 1.5.ltoreq.x.ltoreq.3, 0.4.ltoreq.y.ltoreq.0.95, and
0.15.ltoreq.z.ltoreq.1.
[0038] In an embodiment, the thickness of the CE layer is in a
range 80 nm to 500 nm.
[0039] The electrolyte layer 206 includes a solid electrolyte that
allows ions to migrate through the electrolyte layer 206 as an
electrical field across the electrolyte layer is changed from the
high transmission state to the low transmission state, or vice
verse. In an embodiment, the electrolyte layer 206 can be a ceramic
electrolyte. In another embodiment, the electrolyte layer 206 can
include a silicate-based or borate-based material. The electrolyte
layer 206 may include a silicate, an aluminum silicate, an aluminum
borate, a borate, a zirconium silicate, a niobate, a borosilicate,
a phosphosilicate, a nitride, an aluminum fluoride, or another
suitable ceramic material. Other suitable ion-conducting materials
can be used, such as tantalum pentoxide or a garnet or perovskite
material based on a lanthanide-transition metal oxide. In another
embodiment, as formed, the electrolyte layer 206 may include mobile
ions. Thus, lithium-doped or lithium-containing compounds of any of
the foregoing may be used. Alternatively, a separate lithiation
operation, such as sputtering lithium, may be performed. The
electrolyte layer 206 may include a plurality of layers having
alternating or differing materials, including reaction products
between at least one pair of neighboring layers. In a further
embodiment, the refractive index and thickness of the electrolyte
layer 206 are selected to have acceptable visible light
transmission while keeping electronic current very low. In another
embodiment, the electrolyte layer 206 has low or no significant
electronic conductivity (e.g., low leakage current). The thickness
of the electrolyte layer 206 can be in a range of 10 nm to 70
nm.
[0040] The method can further include forming a barrier layer over
the electrochromic stack, at block 122 in FIG. 1. The barrier layer
helps to prevent or at least reduce the likelihood that (1) Ag from
a subsequently-formed layer migrated into an underlying layer, (2)
a mobile ion from an underlying layer migrates into a
subsequently-formed layer, or both (1) and (2). Accordingly, the
barrier layer helps to allow a conductive layer including Ag to be
used without causing premature device failure or unacceptable
performance.
[0041] FIG. 3 includes an illustration of the electrochromic device
after forming barrier layer 309 over the layer 208. The barrier
layer 309 can include an oxide or a nitride of a trivalent,
tetravalent, or pentavalent metal. In an embodiment, the barrier
layer 309 can include Al.sub.2O.sub.3, TiO.sub.2, Ta.sub.2O.sub.5,
ZrO.sub.2, HfO.sub.2, another suitable metal oxide, or the like. In
a particular embodiment, the barrier layer 309 includes
Al.sub.2O.sub.3 or TiO.sub.2. In another embodiment, the barrier
layer 309 can include AlN, TiN, TaN, ZrN, HfN, another suitable
metal nitride, or the like. In a further embodiment, the barrier
layer 309 can include a metal-silicon compound, such as a titanium
silicon nitride, a tantalum silicon nitride, or a tungsten silicon
nitride.
[0042] The thickness of the barrier layer 309 is selected to
provide sufficient transmission of visible light (e.g., >75%
transmission of electromagnetic radiation at wavelengths in a range
of 400 nm to 700 nm). In an embodiment, the thickness of the
barrier layer 309 is sufficient to provide a continuous layer. The
thickness of the barrier layer 309 is at least 5 nm, at least 11
nm, or at least 15 nm. The barrier layer 309 may not be so thick as
to prevent charge carriers from tunneling or otherwise passing
through the barrier layer 309. The thickness of the barrier layer
309 is at most 200 nm, at most 100 nm, or at most 80 nm. In a
particular embodiment, the barrier layer 309 is in a range of 5 nm
to 200 nm, 11 nm to 100 nm, or 15 nm to 80 nm.
[0043] The barrier layer 309 can be formed as a conformal layer
over layer 208. In an embodiment, the barrier layer 309 can be
formed by atomic layer deposition (ALD). In another embodiment, the
barrier layer 309 can be formed by chemical vapor deposition (CVD).
The deposition may be performed using a plasma-assisted technique
or without plasma assistance. ALD can have better thickness control
as compared to CVD. Accordingly, ALD is well suited to forming the
barrier layer 309.
[0044] A metal-containing precursor for the barrier layer 309 can
include an organometallic compound, a metal halide, or a metal
carbonyl compound. In an embodiment, the organometallic compound
includes a metal alkyl compound, a metal alkoxide compound, or a
dialkyl-amino metal, wherein each alkyl group or alkoxide group has
no more than four carbon atoms. In a particular embodiment, the
organometallic compound includes a tetrakis(alkyl) metal (IV), a
tetrakis(dialkylamino) metal (IV), a tetrakis(alkoxide) metal (IV),
or a bis(alkylcyclopentadienyl)alkoxyalkyl metal (IV), wherein each
alkyl group and each alkoxide group has at most four carbon atoms.
In another particular embodiment the organometallic compound
includes a pentakis(alkyl) metal (V), a pentakis(dialkylamino)
metal (V), or a pentakis(alkoxide) metal (V), wherein each alkyl
group and each alkoxide group has at most four carbon atoms. When
an aluminium-containing compound is being formed, the
organometallic compound can includes Al(CH.sub.3).sub.3. In a
particular embodiment, the barrier layer 309 includes silicon, and
the barrier layer 309 can be formed using a silicon-containing gas.
For example, the barrier layer 309 may include a titanium silicon
nitride, a tantalum silicon nitride, or a tungsten silicon nitride.
When the barrier layer 309 includes a metal oxide, the metal
precursor can be reacted with H.sub.2O, H.sub.2O.sub.2, O.sub.2, or
O.sub.3, or any combination thereof. When the barrier layer 309
includes a metal nitride, the metal precursor can be reacted with
gas can include NH.sub.3, N.sub.2H.sub.2, or a mixture of N.sub.2
and H.sub.2, or any combination thereof.
[0045] For ALD, a monolayer of the metal-containing precursor can
be formed along an exposed surface. The metal-containing precursor
can be reacted with an oxygen-containing gas or a
nitrogen-containing gas to form the metal oxide or nitride. The
deposition of the monolayer and reaction are iterated until the
desired thickness of the layer is achieved. The barrier layer 309
is dense, conformal, and substantially pinhole free. The deposition
temperature may be performed at a temperature less than 100.degree.
C.
[0046] The method can further include forming a transparent
conductive layer including Ag over the barrier layer, at block 124
in FIG. 1. Referring to FIG. 4, a transparent conductive layer 410
overlies the transparent substrate 200, the transparent conductive
layer 202, the electrode layer 204, the electrolyte layer 206, the
electrode layer 208, and the barrier layer 309. The transparent
conductive layer 410 can include one or more films. One of the
films includes Ag to provide good conductivity and low emissivity.
Thus, a separate low-emissivity layer spaced apart from the
electrochromic stack is not needed. In an embodiment, an oxide film
or a nitride film may lie along one or both sides of the Ag film.
In an embodiment, a seed film may be used. In a particular
embodiment, the seed layer may include a transparent conductive
oxide. The transparent conductive oxide can include a doped metal
oxide, such as a doped zinc oxide or a doped tin oxide, either of
which may be doped with a Group 13 element, such as Al, Ga, or In.
Indium tin oxide (ITO) and aluminum zinc oxide (AZO) are exemplary,
non-limiting materials that can be used.
[0047] The barrier layer 309, a film within the transparent
conductive layer 410, or both can include a material with a
relatively high index of refraction. The transparent conductive
layer 410 may also include a film having the intermediate index of
refraction that is between the indices of refraction of (1) the
barrier layer 309 or a film within the transparent conductive layer
(e.g., AZO or ITO) and (2) Ag, air or another gas. The film of
intermediate index of refraction can help to reduce total
reflection. In an embodiment, the film having the intermediate
index of refraction can include SiO.sub.2. For any film within the
transparent conductive layer 402 that includes a material that is
normally considered an insulator (e.g., SiO.sub.2, Si.sub.3N.sub.4,
or the like) may have a thickness less than 50 nm.
[0048] In another embodiment, the transparent conductive layer 402
may include a thin blocker layer can be used and may include NiCr,
Ti, NiCrO.sub.x, TiO.sub.x, or a mixture thereof, wherein
1.ltoreq.x.ltoreq.2, to reduce the likelihood of oxidizing Ag when
AZO or another transparent conductive oxide is in contact with the
Ag. A blocker layer may overlie or underlie the Ag or blocker
layers may overlie and underlie the Ag. The blocker layer may not
be required in all embodiments. When present, the blocker layer can
have a thickness in a range of 0.5 nm to 5 nm.
[0049] Many different film stacks may be used for the transparent
conductive layer 410. An exemplary, non-limiting stack includes
SiO.sub.2/AZO/Xo/Ag/Xu/AZO/SiO.sub.2, where Xo is the blocker layer
overlying the Ag, and Xu is the blocker layer underlying the Ag. Xo
and Xu can have any one of the compositions and thicknesses
previously described with respect to the optional blocker layer. Xo
and Xu may have the same composition or different compositions and
may have the same thickness or different thicknesses. In another
embodiment, the top and bottom part of the stack may be a
transparent oxide layer, a transparent nitride layer, or any
combination thereof. Thus, SiO.sub.2 in the prior example may be
replaced by or used in conjunction with Si.sub.3N.sub.4, TiO.sub.x,
SnO.sub.x, SnZnO.sub.x (composition Sn:Zn can vary from 10:90 to
90:10), SiZrO.sub.x, SiZrN, ZrO.sub.x, wherein
1.ltoreq.x.ltoreq.2.
[0050] Other than the barrier layer 309, all other layers within
the EC stack can be formed by physical vapor deposition.
Alternatively, any one or more such other layers may alternatively
be formed using chemical vapor deposition, atomic layer deposition,
another suitable technique, or any combination thereof.
[0051] In the embodiment as illustrated, the method can include
removing portions of the electrochromic stack at areas where bus
bars will be subsequently formed, at block 142 of FIG. 1. In FIG.
5, the layers 204, 206, 208, 309, and 410 are patterned to define
openings 502 and 510, in which the transparent conductive layer 202
is exposed. In another embodiment, the opening 510 may extend to a
different depth as compared to opening 502. For example, the
opening 510 may extend to a variety of different depths, so long as
the transparent conductive layer 410 is exposed within the opening
510. For example, the layer 410 is patterned such that an Ag film
within the transparent conductive layer 410 is exposed along the
bottom of the opening 510. In another embodiment, the opening 510
can be extended through the transparent conductive layer 202 such
that the substrate 200 is exposed along the bottom of the opening
510. After reading this specification, skilled artisans will be
able to determine a depth for the opening 510 that meets the needs
or desires for a particular application. The removal of the
portions of the electrochromic stack may be performed using an
ablating technique, such as laser ablation, or may be removed using
an etching technique. After reading this specification, skilled
artisans will understand that other portions of the electrochromic
device may also have laser removal operations to pattern or remove
portions of one or more layers at this time or at another time for
reasons independent of bus bar formation. Furthermore, a bus bar
may be formed over all of the layers of the EC stack and not be
formed within a laser line.
[0052] The method can further include forming bus bars, at block
144 in FIG. 1. The bus bars can be formed by depositing a bus bar
precursor. In an embodiment, the bus bar precursor can be a silver
paste. The bus bar precursor can be fired to form the bus bars.
FIG. 6 includes as illustration after forming the bus bars 602 and
610. In an embodiment, the thickness of the bus bars 602 and 610 in
a range of 12 microns to 40 microns. After reading this
specification, skilled artisans will be able to determine a
thickness to provide needed or desired electrical properties of the
bus bars 602 and 610.
[0053] The method can further include performing finishing
operations, at block 162 in FIG. 1. The particular finishing
operation may depend on the particular application. As illustrated
in FIG. 7, portions of the layers 410 and 309 are removed at
opening 702, so that the bus bar 602 is not electrically connected
to most of the transparent conductive layer 410. Thus, the bus bar
602 is a principal connection for the transparent conductive layer
202, and the bus bar 610 is a principal connection for the
transparent conductive layer 410. At this point in the process, an
electrochromic device 700 is formed. In another embodiment (not
illustrated), the bus bar 602 is formed such that it does not
contact the side of the stack within the opening 502, as
illustrated in FIG. 5. In this embodiment, the removal of the
portions of the layers 410 and 309 is not needed. In a further
embodiment, the opening 702 may not extend through the barrier
layer 309 if the barrier layer 309 is an electronic insulator.
[0054] In a further embodiment, the electrochromic device 700 can
be at least a part of a window for a vehicle. In a vehicle
application, the electrochromic device 700 may be bent or otherwise
shaped to conform to the body shape of the vehicle. The temperature
for bending or otherwise shaping the electrochromic device can be
in a temperature of at least 600.degree. C. In a particular
embodiment, the temperature is in a range of 600.degree. C. to
700.degree. C. The heat may be applied locally. The barrier layer
309 can help to reduce the likelihood of significantly adversely
affecting the transparent conductive layer 410 during bending or
otherwise shaping. The sintering portion of firing to form the bus
bars may occur during the heat cycle used to bend the
electrochromic device.
[0055] In an embodiment, an insulated glass unit 800 may be formed,
as illustrated in FIG. 8. The electrochromic device 700 can be
coupled to a counter substrate 802 that is transparent to visible
light. The counter substrate 802 may include a tempered or
strengthened glass. In a particular embodiment, an adhesive (not
illustrated) can be used between the electrochromic device 700 and
the counter substrate 802. The insulated glass unit 800 can further
include a glass panel 804, spacers 822, and a sealing material 824.
Similar to the counter substrate 802, the glass panel 804 can
include a tempered or strengthened glass. Furthermore, the glass
panel 804 may be part of a laminate that can include a solar
control layer, similar to the solar control layer as previously
described with respect to the substrate 200. The insulated glass
unit may include a solar control layer within the substrate 200 and
not the glass panel 804, a solar control layer within or attached
to the glass panel 804, or solar control layer with each of the
substrate 200 and within or attached to the glass panel 804 may be
used. In this last alternative, the solar control layers may serve
different functions. For example, the solar control layer closer to
the outside of a building may help to reject near infrared
radiation, and the other solar control layer closer to the inside
of the building may include a low emissivity material or help to
rejection ultraviolet radiation. During a sealing operation, an
inert gas (such as argon or krypton), N.sub.2, air, or the like,
may fill the gap 806.
[0056] Optionally, after forming the electrochromic device 700, the
electrochromic device 700 may be annealed to reduce stress or for
another purpose. The anneal may be performed separately from the
firing. In another embodiment, the sintering portion of the firing
may be combined with the anneal operation. The barrier layer 309
can allow a higher temperature for the anneal, an oxidizing
ambient, such as air, or both to be used without significantly
adversely affecting the transparent conductive layer 410. The
anneal may be performed at a temperature in a range of 100.degree.
C. to 600.degree. C.
[0057] A means for preventing (1) the mobile ion from migrating
into the first transparent conductive layer, (2) Ag from migrating
into the electrochromic layer or counter electrode layer, or both
(1) and (2) helps to keep the electrochromic device operational
longer when a Ag film is used as part of the transparent conductive
layer 410. As previously described, the barrier layer 309 provides
a means for preventing the mobile ion or Ag migration.
[0058] In another embodiment, the transparent conductive layer 202
can have a composition as previously described with respect to the
transparent conductive layer 410. A barrier layer can be used
between the layers 202 and 204 and have a composition and be formed
as previously described with respect to the barrier layer 309.
[0059] Embodiments as described herein can allow for the
integration of a low emissivity film within an EC stack and still
have good operational characteristics. The barrier layer 309 or
other means for preventing mobile ion or Ag migration can help to
reduce or eliminate migration of mobile ions, such as Li+, into the
transparent conductive layer, or migration of Ag into the EC or CE
layers. Thus, a low emissivity film separate and spaced apart from
the EC stack is not needed. Within the transparent conductive
layer, the low emissivity film can be an Ag film that has good
conductivity and has a thickness to allow sufficient transmission
of visible light through the electrochromic device.
[0060] Many different aspects and embodiments are possible. Some of
those aspects and embodiments are described below. After reading
this specification, skilled artisans will appreciate that those
aspects and embodiments are only illustrative and do not limit the
scope of the present invention. Exemplary embodiments may be in
accordance with any one or more of the ones as listed below.
Embodiment 1
[0061] An electrochromic device comprising: [0062] a substrate;
[0063] an electrochromic layer or a counter electrode layer over
the substrate, wherein the electrochromic or counter electrode
layer includes a mobile ion; [0064] a first transparent conductive
layer over the substrate and including Ag; and [0065] a barrier
layer disposed between first transparent conductive layer and the
electrochromic or counter electrode layer.
Embodiment 2
[0066] An electrochromic device comprising: [0067] a substrate;
[0068] an electrochromic layer or a counter electrode layer over
the substrate, wherein the electrochromic or counter electrode
layer includes a mobile ion; [0069] a first transparent conductive
layer over the substrate and including Ag; and [0070] means for
preventing: [0071] (1) the mobile ion from migrating into the first
transparent conductive layer; [0072] (2) Ag from migrating into the
electrochromic layer or counter electrode layer; or both (1) and
(2).
Embodiment 3
[0073] The electrochromic device of Embodiment 1 or 2, wherein the
electrochromic device includes an electrochromic stack comprising:
[0074] the first transparent conductive layer; [0075] the barrier
layer; [0076] the electrochromic layer; [0077] the counter
electrode layer; and [0078] a second transparent conductive layer,
[0079] wherein the first transparent conductive layer is coupled to
one of the electrochromic layer and the counter electrode layer,
and the second transparent conductive layer is coupled to the other
of the electrochromic layer and the counter electrode layer.
Embodiment 4
[0080] A process of forming an electrochromic device comprising:
[0081] providing a substrate; [0082] forming an electrochromic
layer or a counter electrode layer over the substrate, wherein
after forming the electrochromic or counter electrode layer, the
electrochromic or counter electrode layer includes a mobile ion;
[0083] forming a barrier layer over the substrate; and [0084]
forming a first transparent conductive layer over the substrate and
including Ag, [0085] wherein forming the barrier layer is formed
between forming the electrochromic or counter electrode layer and
forming the first transparent conductive layer.
Embodiment 5
[0086] The process of Embodiment 4, wherein forming the barrier
layer is performed using atomic layer deposition.
Embodiment 6
[0087] The process of Embodiment 4, wherein forming the barrier
layer is performed using chemical vapor deposition.
Embodiment 7
[0088] The process of any one of Embodiments 4 to 6, wherein
forming the barrier is performed using a metal-containing precursor
including an organometallic compound, a metal halide, or a metal
carbonyl compound.
Embodiment 8
[0089] The process of Embodiment 7, wherein the organometallic
compound includes a metal alkyl compound, a metal alkoxide
compound, or a dialkyl-amino metal, wherein each alkyl group or
alkoxide group has no more than four carbon atoms.
Embodiment 9
[0090] The process of Embodiment 7 or 8, wherein the organometallic
compound includes a tetrakis(alkyl) metal (IV), a
tetrakis(dialkylamino) metal (IV), a tetrakis(alkoxide) metal (IV),
or a bis(alkylcyclopentadienyl)alkoxyalkyl metal (IV), wherein each
alkyl group and each alkoxide group has at most four carbon
atoms.
Embodiment 10
[0091] The process of Embodiment 7 or 8, wherein the organometallic
compound includes a pentakis(alkyl) metal (V), a
pentakis(dialkylamino) metal (V), or a pentakis(alkoxide) metal
(V), wherein each alkyl group and each alkoxide group has at most
four carbon atoms.
Embodiment 11
[0092] The process of any one of Embodiments 7 to 9, wherein the
organometallic compound includes Al(CH.sub.3).sub.3.
Embodiment 12
[0093] The process of any one of Embodiments 4 to 11, wherein
forming the barrier layer is performed using H.sub.2O,
H.sub.2O.sub.2, O.sub.2, or O.sub.3, or any combination
thereof.
Embodiment 13
[0094] The process of any one of Embodiments 4 to 12, wherein
forming the barrier layer is performed using NH.sub.3,
N.sub.2H.sub.2, or a mixture of N.sub.2 and H.sub.2, or any
combination thereof.
Embodiment 14
[0095] The process of any one of Embodiments 4 to 13, wherein
forming the barrier layer is performed using a silicon-containing
gas.
Embodiment 15
[0096] The process of any one of Embodiments 4 to 14, wherein
forming the barrier layer is formed using a plasma-assisted
technique.
Embodiment 16
[0097] The process of any one of Embodiments 4 to 15, further
comprising: [0098] forming the other of the electrochromic layer or
the counter electrode layer; and [0099] forming a second
transparent conductive layer, [0100] wherein the first transparent
conductive layer is coupled to one of the electrochromic layer and
the counter electrode layer, and the second transparent conductive
layer is coupled to the other of the electrochromic layer and the
counter electrode layer.
Embodiment 17
[0101] The electrochromic device or the process of any one of the
preceding Embodiments, wherein the barrier layer is conformal.
Embodiment 18
[0102] The electrochromic device or the process of any one of the
preceding Embodiments, wherein the barrier layer has a thickness of
at least 5 nm, at least 11 nm, or at least 15 nm.
Embodiment 19
[0103] The electrochromic device or the process of any one of the
preceding Embodiments, wherein the barrier layer has a thickness of
at most 200 nm, at most 100 nm, or at most 80 nm.
Embodiment 20
[0104] The electrochromic device or the process of any one of the
preceding Embodiments, wherein the barrier layer has a thickness of
in a range of 5 nm to 200 nm, 11 nm to 100 nm, or 15 nm to 80
nm.
Embodiment 21
[0105] The electrochromic device or the process of any one of
Embodiments 4 to 12 and 15 to 20, wherein the barrier layer
includes a metal oxide.
Embodiment 22
[0106] The electrochromic device or the process of Embodiment 21,
wherein the barrier layer includes Al.sub.2O.sub.3.
Embodiment 23
[0107] The electrochromic device or the process of Embodiment 21,
wherein the barrier layer includes TiO.sub.2.
Embodiment 24
[0108] The electrochromic device or the process of any one of
Embodiments 4 to 11, 13, and 15 to 20, wherein the barrier layer
includes a metal nitride.
Embodiment 25
[0109] The electrochromic device or the process of Embodiment 24,
wherein the barrier layer includes AlN.
Embodiment 26
[0110] The electrochromic device or the process of Embodiment 24,
wherein the barrier layer includes TiN.
Embodiment 27
[0111] The electrochromic device or the process of any one of
Embodiments 4, 11, and 14 to 20, wherein the barrier layer includes
metal-silicon compound.
Embodiment 28
[0112] The electrochromic device or the process of Embodiment 27,
wherein the barrier layer includes a titanium silicon nitride, a
tantalum silicon nitride, or a tungsten silicon nitride.
Embodiment 29
[0113] The electrochromic device or the process of any one of the
preceding Embodiments, wherein the barrier layer is spaced apart
from the Ag within the first transparent conductive layer.
Embodiment 30
[0114] The electrochromic device or the process of any one of the
preceding Embodiments, further comprising a first transparent
conductive oxide between the Ag and the barrier layer.
Embodiment 31
[0115] The electrochromic device or the process of any one of the
preceding Embodiments, further comprising a second transparent
conductive oxide along a side of the Ag that is opposite the
barrier layer.
Embodiment 32
[0116] The electrochromic device or the process of any one of the
preceding Embodiments, further comprising an electrolyte layer
between the electrochromic layer and the counter electrode
layer.
[0117] Note that not all of the activities described above in the
general description or the examples are required, that a portion of
a specific activity may not be required, and that one or more
further activities may be performed in addition to those described.
Still further, the order in which activities are listed is not
necessarily the order in which they are performed.
[0118] Certain features that are, for clarity, described herein in
the context of separate embodiments, may also be provided in
combination in a single embodiment. Conversely, various features
that are, for brevity, described in the context of a single
embodiment, may also be provided separately or in any
subcombination. Further, reference to values stated in ranges
includes each and every value within that range.
[0119] Benefits, other advantages, and solutions to problems have
been described above with regard to specific embodiments. However,
the benefits, advantages, solutions to problems, and any feature(s)
that may cause any benefit, advantage, or solution to occur or
become more pronounced are not to be construed as a critical,
required, or essential feature of any or all the claims.
[0120] The specification and illustrations of the embodiments
described herein are intended to provide a general understanding of
the structure of the various embodiments. The specification and
illustrations are not intended to serve as an exhaustive and
comprehensive description of all of the elements and features of
apparatus and systems that use the structures or methods described
herein. Separate embodiments may also be provided in combination in
a single embodiment, and conversely, various features that are, for
brevity, described in the context of a single embodiment, may also
be provided separately or in any subcombination. Further, reference
to values stated in ranges includes each and every value within
that range. Many other embodiments may be apparent to skilled
artisans only after reading this specification. Other embodiments
may be used and derived from the disclosure, such that a structural
substitution, logical substitution, or another change may be made
without departing from the scope of the disclosure. Accordingly,
the disclosure is to be regarded as illustrative rather than
restrictive.
* * * * *