U.S. patent application number 16/498119 was filed with the patent office on 2021-10-28 for thermally activated delayed fluorescence material and organic light emitting diode display device.
The applicant listed for this patent is WUHAN CHINA STAR OPTOELECTRONICS SEMICONDUCTOR DISPLAY TECHNOLOGY CO., LTD.. Invention is credited to Jiajia LUO, Qu ZHANG.
Application Number | 20210336150 16/498119 |
Document ID | / |
Family ID | 1000005710599 |
Filed Date | 2021-10-28 |
United States Patent
Application |
20210336150 |
Kind Code |
A1 |
LUO; Jiajia ; et
al. |
October 28, 2021 |
THERMALLY ACTIVATED DELAYED FLUORESCENCE MATERIAL AND ORGANIC LIGHT
EMITTING DIODE DISPLAY DEVICE
Abstract
A thermally activated delayed fluorescent material includes a
structural formula (I) as follows: ##STR00001## and D1 and D2 are
different electron donors. In addition, an organic light emitting
diode display device includes an anode, a cathode, and an organic
functional layer disposed between the anode and the cathode. The
organic functional layer includes a thermally activated delayed
fluorescent material, and the thermally activated delayed
fluorescent material includes a structural formula (I).
Inventors: |
LUO; Jiajia; (Wuhan, Hubei,
CN) ; ZHANG; Qu; (Wuhan, Hubei, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
WUHAN CHINA STAR OPTOELECTRONICS SEMICONDUCTOR DISPLAY TECHNOLOGY
CO., LTD. |
Wuhan, Hubei |
|
CN |
|
|
Family ID: |
1000005710599 |
Appl. No.: |
16/498119 |
Filed: |
May 15, 2019 |
PCT Filed: |
May 15, 2019 |
PCT NO: |
PCT/CN2019/086994 |
371 Date: |
September 26, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C09K 11/06 20130101;
C09K 2211/1022 20130101; H01L 51/0072 20130101; C09K 2211/1007
20130101; H01L 51/0067 20130101; C07D 401/14 20130101; C09K
2211/1014 20130101; H01L 51/5072 20130101; H01L 51/5012
20130101 |
International
Class: |
H01L 51/00 20060101
H01L051/00; C09K 11/06 20060101 C09K011/06; C07D 401/14 20060101
C07D401/14 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 26, 2019 |
CN |
201910234700.X |
Claims
1. A thermally activated delayed fluorescent material, comprising a
structural formula (I) as follows: ##STR00038## wherein D1 and D2
are different electron donors.
2. The thermally activated delayed fluorescent material according
to claim 1, wherein the D1 comprises one of following chemical
structural formulas: ##STR00039## wherein R1 is selected one from
an oxygen or a C1-C3 alkyl group; ##STR00040## wherein the R2
selected one from a C1-C3 alkyl or a silane group; ##STR00041##
3. The thermally activated delayed fluorescent material according
to claim 1, wherein the D1 is selected one from the group
consisting of ##STR00042## and ##STR00043##
4. The thermally activated delayed fluorescent material according
to claim 1, wherein the D2 has a structural formula (I) as follows:
##STR00044## wherein the R3 is selected one from a hydrogen, a
C1-C4 alkyl, an alkoxy, or an aryl.
5. The thermally activated delayed fluorescent material according
to claim 4, wherein the D2 is selected one from the group
consisting of ##STR00045##
6. An organic light emitting diode display device, comprising an
anode, a cathode, and an organic functional layer disposed between
the anode and the cathode, wherein the organic functional layer
comprises a thermally activated delayed fluorescent material, and
the thermally activated delayed fluorescent material comprises a
structural formula (I) as follows: ##STR00046## wherein the D1 is
selected one from the group consisting of ##STR00047## and D2 is
selected one from the group consisting of ##STR00048##
7. The organic light emitting diode display device according to
claim 6, wherein the thermally activated delayed fluorescent
material is a fluorescent host material used in the organic light
emitting diode display device.
8. The organic light emitting diode display device according to
claim 6, wherein the thermally activated delayed fluorescent
material is an electron transporting material used in the organic
light emitting diode display device.
9. A thermally activated delayed fluorescent material, comprising a
structural formula (I) as follows: ##STR00049## wherein D1 and D2
are different electron donors, and the D1 comprises one of
following chemical structural formulas: ##STR00050## wherein R1 is
selected one from an oxygen or a C1-C3 alkyl group; ##STR00051##
wherein the R2 selected one from a C1-C3 alkyl or a silane group;
##STR00052## and the D2 has a structural formula (I) as follows:
##STR00053## wherein the R3 is selected one from a hydrogen, a
C1-C4 alkyl, an alkoxy, or an aryl.
10. The thermally activated delayed fluorescent material according
to claim 9, wherein the D1 is selected one from the group
consisting of ##STR00054##
11. The thermally activated delayed fluorescent material according
to claim 9, wherein the D2 is selected one from the group
consisting of ##STR00055##
12. The thermally activated delayed fluorescent material according
to claim 9, wherein the organic functional layer comprises a
thermally activated delayed fluorescent material.
13. The thermally activated delayed fluorescent material according
to claim 9, wherein the thermally activated delayed fluorescent
material is a fluorescent host material used in the organic light
emitting diode display device.
14. The thermally activated delayed fluorescent material according
to claim 9, wherein the thermally activated delayed fluorescent
material is an electron transporting material used in the organic
light emitting diode display device.
Description
BACKGROUND OF INVENTION
Field of Invention
[0001] The present invention relates to a field of organic
electroluminescent materials, and more particularly to a thermally
activated delayed fluorescence material and an organic light
emitting diode display device.
Description of Prior Art
[0002] Dominant guest luminescent materials are critical for
affecting luminescent efficiency of organic light emitting diode
(OLED) display devices. Generally, the luminescent guest materials
used in OLED display devices are fluorescence materials. Generally,
a ratio of singlet excitons to triplet excitons in the OLED display
devices is 1:3, so an internal quantum efficiency (IQE) of the OLED
display devices is merely 25%. Therefore, application of
fluorescent electroluminescent devices is greatly limited. The
phosphorescent heavy-metal complexes can achieve 100% IQE by using
singlet and triplet excitons simultaneously due to the spin-orbit
coupling of heavy atoms. However, the used heavy-metals are
precious metals, such as iridium (Ir) or platinum (Pt). The
phosphorescent heavy-metal complexes must be improved in terms of
blue light materials. In addition, pure organic thermally activated
delayed fluorescence materials have a lowest single-triplet level
difference (.DELTA.EST) which is relatively less than ever before,
so that triplet excitons can be transformed to a singlet state by
reverse intersystem crossing (RISC) and then are illuminated when
jumping to a ground state transition by radiation. Therefore,
single and triplet excitons can be simultaneously used and achieve
100% IQE.
[0003] As for the thermally activated delayed fluorescence
materials, a high reaction rate constant of reverse intersystem
enthalpy constant (k.sub.RISC) and a high photoluminescence quantum
yield (PLQY) are necessary for fabricating OLED display devices
having high luminescent efficiency. Currently, the thermally
activated delayed fluorescence materials with the above features
are still relatively lacking as compared with heavy metal
complexes.
SUMMARY OF INVENTION
[0004] A novel deep blue thermally activated delayed fluorescent
material having high thermal stability and a high ratio of
thermally activated delayed fluorescent materials to
photoluminescence quantum yield to solve the problems in the prior
art.
[0005] A thermally activated delayed fluorescent material includes
a structural formula (I) as follows:
##STR00002##
and D1 and D2 are different electron donors.
[0006] In one embodiment, the D1 includes one of following chemical
structural formulas:
##STR00003##
and R1 is selected one from an oxygen or a C1-C3 alkyl group;
##STR00004##
and the R2 selected one from a C1-C3 alkyl or a silane group;
##STR00005##
[0007] In one embodiment, the D1 is selected one from the group
consisting of
##STR00006##
[0008] In one embodiment, and the D2 has a structural formula (I)
as follows:
##STR00007##
and the R3 is selected one from a hydrogen, a C1-C4 alkyl, an
alkoxy, or an aryl.
[0009] In one embodiment, the D2 is selected one from the group
consisting of
##STR00008##
[0010] An organic light emitting diode display device includes an
anode, a cathode, and an organic functional layer disposed between
the anode and the cathode, and the organic functional layer
includes a thermally activated delayed fluorescent material, and
the thermally activated delayed fluorescent material includes a
structural formula (I) as follows:
##STR00009##
and the D1 is selected one from the group consisting of
##STR00010##
and D2 is selected one from the group consisting of
##STR00011##
[0011] In one embodiment, and the thermally activated delayed
fluorescent material is a fluorescent host material used in the
organic light emitting diode display device.
[0012] In one embodiment, and the thermally activated delayed
fluorescent material is an electron transporting material used in
the organic light emitting diode display device.
[0013] A thermally activated delayed fluorescent material includes
a structural formula (I) as follows:
##STR00012##
and D1 and D2 are different electron donors, and the D1 includes
one of following chemical structural formulas:
##STR00013##
and R1 is selected one from an oxygen or a C1-C3 alkyl group;
##STR00014##
and the R2 selected one from a C1-C3 alkyl or a silane group;
##STR00015##
and the D2 has a structural formula (I) as follows:
##STR00016##
and the R3 is selected one from a hydrogen, a C1-C4 alkyl, an
alkoxy, or an aryl.
[0014] In one embodiment, and the D1 is selected one from the group
consisting of
##STR00017##
[0015] In one embodiment, and the D2 is selected one from the group
consisting of
##STR00018##
[0016] In one embodiment, the organic functional layer includes a
thermally activated delayed fluorescent material.
[0017] In one embodiment, the thermally activated delayed
fluorescent material is a fluorescent host material used in the
organic light emitting diode display device.
[0018] In one embodiment, the thermally activated delayed
fluorescent material is an electron transporting material used in
the organic light emitting diode display device.
[0019] A novel deep blue thermally activated delayed fluorescent
material having high thermal stability and high ratio of thermally
activated delayed fluorescent materials to photoluminescence
quantum yield, and thus an organic light emitting diode display
device having high luminescent efficiency is achieved.
BRIEF DESCRIPTION OF DRAWINGS
[0020] FIG. 1 is a photoluminescence spectrum of a thermally
activated delayed fluorescent material in a toluene solution
according to one embodiment of the present invention.
[0021] FIG. 2 is a schematic view of an organic light emitting
diode display device using a thermally activated delayed
fluorescent material as a light emitting layer according to one
embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0022] Generally, a thermally activated delayed fluorescent
material has a molecular structure in which an electron donor and
an electron acceptor are combined. In the embodiment of the present
invention, organic thermally activated delayed fluorescence
materials have a lowest single-triplet level difference
(.DELTA.EST) which is relatively less than ever before and a high
photoluminescence quantum yield by adjusting a twist angle between
the electron donor and the electron acceptor and charge transfer
property, and thus an organic light emitting diode display device
having high luminescent efficiency is achieved.
[0023] A thermally activated delayed fluorescent material,
comprising a structural formula (I) as follows:
##STR00019##
and D1 and D2 are different electron donors.
[0024] Specifically, D1 includes one of following chemical
structural formulas:
##STR00020##
and R1 is selected one from an oxygen or a C1-C3 alkyl group;
##STR00021##
and the R2 selected one from a C1-C3 alkyl or a silane group;
##STR00022##
Preferably, the D1 is selected one from the group consisting of
##STR00023##
[0025] Specifically, the D2 has a structural formula (I) as
follows:
##STR00024##
and the R3 is selected one from a hydrogen, a C1-C4 alkyl, an
alkoxy, or an aryl. Preferably, the D2 is selected one from the
group consisting of
##STR00025##
[0026] The steps for synthesizing the thermally activated delayed
fluorescent materials of various embodiments of the present
invention are further described below.
[0027] A synthetic route for
##STR00026##
is described as follows:
##STR00027##
[0028] 4-Bromothiophenol (2.36 g, 10 mmol), 3,6-dichloropyridazine
(1.49 g, 10 mmol), PdCl(CH.sub.3H.sub.5).sub.2 (0.018 g, 0.05
mmol), 1,1'-Ferrocenediyl-bis(diphenylphosphine), dppf, (0.095 g,
0.2 mmol), and tBuONa (1.15 g, 12 mmol) are added to a 250 mL
two-neck bottle and are vacuumed for three times. Then, 80 mL
anhydrous, degassed toluene is added to the two-neck bottle under
an argon atmosphere, and a reaction is performed at 120.degree. C.
for 17 hours, and reaction solution is cooled to room temperature
and poured 200 mL into ice water. Then, the reaction solution is
extracted with ethyl acetate (100 mL) for three times and combined
with an organic phase, and the reaction solution is spun and dried.
Next, the reaction solution is isolated and purified by column
chromatography having a stationary phase of silica gel, in which a
volume ratio of ethyl acetate to hexane is 1:9, to obtain a yellow
oily liquid of 2.14 g, and a yield is 71%. Product identification
data: .sup.1H NMR (300 MHz, CD.sub.2Cl.sub.2, .delta.): 8.00 (d,
J=7.5 Hz, 1H), 7.76 (m, 2H), 7.53 (m, 2H), 7.14 (d, J=7.5 Hz,
1H).
[0029] Next, 3-(4-bromothio)-6-chloropyridazine (2.1 g, 7 mmol),
4-iodobenzene-1-thiol (2.36 g, 10 mmol), cesium carbonate
(CS.sub.2CO.sub.3, 3.26 g, 10 mmol) are added to a 100 mL two-neck
bottle and are vacuumed for three times. Then, 50 mL anhydrous,
degassed toluene is added to the two-neck bottle under an argon
atmosphere, and a reaction is performed at 90.degree. C. for 12
hours, and the reaction solution is cooled to room temperature and
poured into 50 mL ice water. Then, the reaction solution is
extracted with dichloromethane for three times and combined with an
organic phase, and the reaction solution is spun and dried. Next,
the reaction solution is isolated and purified by column
chromatography having a stationary phase of silica gel, in which a
volume ratio of ethyl acetate to hexane is 1:5, to obtain a yellow
oily liquid of 2.8 g, and a yield is 80%. Product identification
data: .sup.1H NMR (300 MHz, CD.sub.2Cl.sub.2, .delta.): 7.73-7.80
(m, 6H), 7.53 (m, 2H), 7.13 (m, 2H).
[0030] 3-(4-bromophenylthio)-6-(4-indodphenylsulfonyl)-pyridazine
(2.5 g, 5 mmol) is added to the 100 mL two-neck bottle and is
dissolved in the dichloromethane solution (20 mL), and then 0.1 M
70% m-CPBA in dichloromethane solution (200 mL, 20 mmol) is added
at 0.degree. C. and performed at 25.degree. C. The reaction mixture
is washed twice with saturated sodium thiosulfate
(Na.sub.2S.sub.2O.sub.3) and combined with an organic phase, and
the reaction solution is spun, dried, and recrystallized with
isopropanol to obtain a yellow solid of 2.4 g, and a yield is 85%.
Product identification data: .sup.1H NMR (300 MHz,
CD.sub.2Cl.sub.2, .delta.): 8.36 (d, J=7.5 Hz, 2H), 8.12 (m, 2H),
7.92 (m, 2H), 7.69 (m, 2H), 7.57 (m, 2H).
[0031] Next, carbazole (0.67 g, 4 mmol),
3-(4-bromophenylsulfonyl)-6-(4-iodophenylsulfonyl)-pyridazine (2.26
g, 4 mmol), Cs.sub.2CO.sub.3 (2.31 g, 5 mmol), CuI (0.06 g, 0.3
mmol), and 18-Crown-6 ((C.sub.2H.sub.4O).sub.6, 26 mg, 0.1 mmol)
are added to a 100 mL two-neck bottle and are vacuumed for three
times. Then, 20 mL anhydrous, degassed
1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU) is added
to the two-neck bottle under an argon atmosphere and performed at
180.degree. C. for 24 hours.
[0032] Next, the reaction solution is cooled to room temperature
and poured into 200 mL ice water and filtered to obtain an
off-white solid, which is then dissolved in dichloromethane, spun,
and dried. Next, the reaction solution is isolated and purified by
column chromatography having a stationary phase of silica gel, in
which a volume ratio of dichloromethane to hexane is 1:3, to obtain
a blue-white powder of 1.72 g, and a yield is 71%. Product
identification data: .sup.1H NMR (300 MHz, CD.sub.2Cl.sub.2,
.delta.): 8.55 (m, 1H), 8.36 (d, J=7.5 Hz, 2H), 8.19 (m, 1H), 8.08
(m, 2H), 7.92-7.94 (m, 5H), 7.69 (m, 2H), 7.19-7.50 (m, 5H).
[0033] Next,
3-(4-bromophenylsulfonyl)-6-(4-carbazolephenylsulfonyl)-pyridazine
(1.51 g, 2.5 mmol), 9,10-dihydro-9,9-diphenyl acridine (1.00 g, 3
mmol), palladium acetate (23 mg, 0.1 mmol), and
tri-tert-butylphosphine tetrafluoroborate (0.09 g, 0.3 mmol) are
added to a 100 mL two-neck bottle. Then, NaOt-Bu (0.30 g, 3 mmol)
is added to the two-neck bottle in a glove box, and 40 mL
anhydrous, degassed toluene is added to the two-neck bottle under
an argon atmosphere, and a reaction is performed at 110.degree. C.
for 24 hours. Then, the reaction solution is cooled to room
temperature and poured into 50 mL ice water, and the reaction
solution is extracted with dichloromethane for three times and
combined with an organic phase, and the reaction solution is spun
and dried. Next, the reaction solution is isolated and purified by
column chromatography having a stationary phase of silica gel, in
which a volume ratio of dichloromethane to hexane is 1:1, to obtain
a white powder of 1.07 g, and a yield is 50%. Finally, a final
product is purified by using a sublimation instrument to obtain 0.6
g target compound (I)
##STR00028##
Product identification data: .sup.1H NMR (300 MHz,
CD.sub.2Cl.sub.2, .delta.): 8.55 (m, 1H), 8.36 (m, 2H), 8.19 (m,
1H), 8.08 (m, 2H), 7.94 (m, 2H), 7.66 (m, 2H), 7.50-7.58 (m, 4H),
7.19-7.26 (m, 20H), 6.95 (m, 2H).
[0034] A synthetic route for
##STR00029##
is described as follows:
##STR00030##
[0035] 3,6-dimethylcarbazole (1.95 g, 10 mmol),
3-(4-bromophenylsulfonyl)-6-(4-iodophenylsulfonyl)-pyridazine (5.65
g, 10 mmol), Cs.sub.2CO.sub.3 (2.31 g, 12 mmol), CuI (0.11 g, 0.6
mmol), and 18-Crown-6 ((C.sub.2H.sub.4O).sub.6, 52 mg, 0.2 mmol)
are added to a 100 mL two-neck bottle and are vacuumed for three
times. Then, 50 mL anhydrous, degassed
1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU) is added
to the two-neck bottle under an argon atmosphere and performed at
180.degree. C. for 24 hours. Next, the reaction solution is cooled
to room temperature and poured into 200 mL ice water and filtered
to obtain an off-white solid, which is then dissolved in
dichloromethane, spun, and dried. Next, the reaction solution is
isolated and purified by column chromatography having a stationary
phase of silica gel, in which a volume ratio of dichloromethane to
hexane is 1:3, to obtain a blue-white powder of 4.1 g, and a yield
is 65%. Product identification data: .sup.1H NMR (300 MHz,
CD.sub.2Cl.sub.2, .delta.): 8.80 (s, 1H), 8.36 (d, J=7.5 Hz, 2H),
8.03-8.08 (m, 3H), 7.89-7.94 (m, 5H), 7.69 (m, 2H), 7.53 (m, 1H),
7.38 (m, 1H), 6.96 (m, 1H), 2.46(s, 6 H).
[0036] Next, 3-(4-bromophenylsulfonyl)-6-(4-(3,
6-dimethylcarbazole) phenylsulfonyl)-pyridazine (3.16 g, 5 mmol),
9,10-dihydro-9,9-diphenyl acridine (1.00 g, 6 mmol), palladium
acetate (45 mg, 0.2 mmol), and tri-tert-butylphosphine
tetrafluoroborate (0.17 g, 0.6 mmol) are added to a 100 mL two-neck
bottle. Then, NaOt-Bu (0.58 g, 6 mmol) is added to the two-neck
bottle in a glove box, and 50 mL anhydrous, degassed toluene is
added to the two-neck bottle under an argon atmosphere, and a
reaction is performed at 110.degree. C. for 24 hours. Then, the
reaction solution is cooled to room temperature and poured into 50
mL ice water, and the reaction solution is extracted with
dichloromethane for three times and combined with an organic phase,
and the reaction solution is spun and dried. Next, the reaction
solution is isolated and purified by column chromatography having a
stationary phase of silica gel, in which a volume ratio of
dichloromethane to hexane is 1:1, to obtain a blue-white powder of
2.1 g, and a yield is 47%. Finally, a final product is purified by
using a sublimation instrument to obtain 1.2 g target compound
(II)
##STR00031##
Product identification data: .sup.1H NMR (300 MHz,
CD.sub.2Cl.sub.2, .delta.): 8.80 (s, 1H), 8.36 (d, J=7.5 Hz, 2H),
8.03-8.08 (m, 3H), 7.89-7.94 (m, 3H), 7.66 (m, 2H), 7.53 (m, 3H),
7.38 (m, 1H), 6.96-7.19 (m, 19H), 2.46(s, 6 H).
[0037] A synthetic route for
##STR00032##
is described as follows:
##STR00033##
[0038] 3,6-diphenylcarbazole (3.19 g, 10 mmol),
3-(4-bromophenylsulfonyl)-6-(4-iodophenylsulfonyl)-pyridazine (5.65
g, 10 mmol), Cs.sub.2CO.sub.3 (2.31 g, 12 mmol), CuI (0.11 g, 0.6
mmol), and 18-Crown-6 ((C.sub.2H.sub.4O).sub.6, 52 mg, 0.2 mmol)
are added to a 100 mL two-neck bottle and are vacuumed for three
times. Then, 50 mL anhydrous, degassed
1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU) is added
to the two-neck bottle under an argon atmosphere and performed at
180.degree. C. for 24 hours. Next, the reaction solution is cooled
to room temperature and poured into 200 mL ice water and filtered
to obtain an off-white solid, which is then dissolved in
dichloromethane, spun, and dried. Next, the reaction solution is
isolated and purified by column chromatography having a stationary
phase of silica gel, in which a volume ratio of dichloromethane to
hexane is 1:3, to obtain a blue-white powder of 4.77 g, and a yield
is 63%. Product identification data: .sup.1H NMR (300 MHz,
CD.sub.2Cl.sub.2, .delta.): 8.36 (d, J=7.5 Hz, 2H), 8.30 (m, 1H),
8.08-8.13 (m, 3H), 7.89-7.99 (m, 7H), 7.69-7.77 (m, 7H), 7.41-7.49
(m, 6H).
[0039] Next, 3-(4-bromophenylsulfonyl)-6-(4-(3,
6-dimethylcarbazole) phenylsulfonyl)-pyridazine (3.78 g, 5 mmol),
9,10-dihydro-9,9-diphenyl acridine (1.00 g, 6 mmol), palladium
acetate (45 mg, 0.2 mmol), and tri-tert-butylphosphine
tetrafluoroborate (0.17 g, 0.6 mmol) are added to a 100 mL two-neck
bottle. Then, NaOt-Bu (0.58 g, 6 mmol) is added to the two-neck
bottle in a glove box, and 50 mL anhydrous, degassed toluene is
added to the two-neck bottle under an argon atmosphere, and a
reaction is performed at 110.degree. C. for 24 hours. Then, the
reaction solution is cooled to room temperature and poured into 50
mL ice water, and the reaction solution is extracted with
dichloromethane for three times and combined with an organic phase,
and the reaction solution is spun and dried. Next, the reaction
solution is isolated and purified by column chromatography having a
stationary phase of silica gel, in which a volume ratio of
dichloromethane to hexane is 1:1, to obtain a white powder of 2.0
g, and a yield is 40%. Finally, a final product is purified by
using a sublimation instrument to obtain 1.1 g target compound
(III)
##STR00034##
Product identification data: .sup.1H NMR (300 MHz,
CD.sub.2Cl.sub.2, .delta.): 8.36 (d, J=7.5 Hz, 2H), 8.30 (m, 1H),
8.08-8.13 (m, 3H), 7.89-7.94 (m, 5H), 7.75-7.77 (m, 5H), 7.66 (m,
2H), 7.41-7.53 (m, 8H), 7.17-7.40 (m, 16 H), 6.95 (m, 2H).
[0040] The lowest singlet energy level (S1) and the lowest triplet
energy level (T1) of the target compound I, the target compound II,
and the target compound III, and the electrochemical energy levels
are as shown in Table 1 below:
TABLE-US-00001 TABLE 1 PL Peak S.sub.1 T.sub.1 .DELTA.E.sub.ST HOMO
LUMO (nm) (eV) (eV) (eV) (eV) (eV) Target compound 449 2.76 2.73
0.03 -5.58 -2.30 (I) Target compound 431 2.88 2.80 0.08 -5.64 -2.31
(II) Target compound 456 2.72 2.66 0.04 -5.53 -2.30 (III)
[0041] Referring to FIG. 1, it is a photoluminescence spectrum of a
thermally activated delayed fluorescent material (compound I,
compound II, and compound III) in a toluene solution according to
one embodiment of the present invention.
[0042] In another embodiment, an organic light emitting diode
display device includes an anode, a cathode, and an organic
functional layer disposed between the anode and the cathode. The
organic functional layer includes a thermally activated delayed
fluorescent material, and the thermally activated delayed
fluorescent material includes a structural formula (I) as
follows:
##STR00035##
and the D1 is selected one from the group consisting of
##STR00036##
and D2 is selected one from the group consisting of
##STR00037##
[0043] Specifically, the thermally activated delayed fluorescent
material is a fluorescent host material or an electron transporting
material used in the organic light emitting diode display
device.
[0044] Referring to FIG. 2, it is a schematic view of an organic
light emitting diode display device using a thermally activated
delayed fluorescent material as a light emitting layer according to
one embodiment of the present invention. The organic light-emitting
diode device includes a glass substrate and a conductive glass
layer 10 made of indium tin oxide (ITO), a hole injection layer 20,
a hole transport layer 30, a light emitting layer 40, an electron
transport layer 50, and a cathode layer 60. Specifically, the hole
injection layer 20 is made of poly 3,4-ethylenedioxythiophene and
polystyrene sulfonate. The electron transport layer 50 is made of
1,3, 5-tris(3-(3-pyridyl)phenyl)benzene. The cathode layer 60 is
made of lithium fluoride and aluminum. The organic light emitting
diode display device can be achieved by a well-known method in the
art, so it will not be described again.
[0045] Furthermore, current, brightness, and voltage
characteristics of organic light emitting diode display device are
achieved by a Keithley source measurement system (Keithley 2400
Sourcemeter, Keithley 2000 Currentmeter) with a silicon photodiode
which is calibrated. An electroluminescence spectrum is measured by
the French JY SPEX CCD3000 spectrometer, and all measurements are
performed at room temperature in the atmosphere.
[0046] The organic light emitting diode display devices (device I,
device II, and device III) use target compound I, target compound
II, and target compound III, respectively, and their performance
data are shown in Table 2 below:
TABLE-US-00002 TABLE 2 maximum Maximum brightness external quantum
Device (cd/A) (CIEx, CIEy) efficiency (%) organic light emitting
14.3 (0.13, 0.13) 16.9% diode display device I organic light
emitting 12.6 (0.13, 0.09) 14.8% diode display device II organic
light emitting 16.3 (0.13, 0.17) 11.8% diode display device III
[0047] In the embodiment of the present invention, the deep blue
high thermally activated delayed fluorescent material has a high
ratio of thermally activated delayed fluorescent material to
photoluminescence quantum yield, thereby an organic light emitting
diode display device having high luminescent efficiency high is
achieved.
[0048] In the above, the present application has been described in
the above preferred embodiments, but the preferred embodiments are
not intended to limit the scope of the invention, and a person
skilled in the art may make various modifications without departing
from the spirit and scope of the application. The scope of the
present application is determined by claims.
* * * * *