U.S. patent number T102,801 [Application Number 06/412,424] was granted by the patent office on 1983-03-01 for silicon solar cell. Invention is credited to Harold J. Hovel.

---

United States Patent	T102,801
Hovel	March 1, 1983

---

Silicon solar cell

Abstract

A high efficiency silicon solar cell (1) may be constructed by providing a two-stage drift field emitter (4) with a 1 micron thickness on a drift field base region (10) with a back surface field region (12). The stage (7) of the drift field emitter adjacent to the junction (8) is moderately doped from 10.sup.18 to 10.sup.16 atoms/cc adjacent the junction to minimize bandgap shrinkage and to maximize carrier lifetime while the stage of the emitter adjacent the surface is highly doped at 10.sup.19 atoms/cc to minimize sheet resistance. The drift field is aiding in both the emitter and base regions. The size of the base (10) is less than an effective diffusion length. There is a difference in doping level in the base depending on the conductivity type of the silicon. For n-conductivity type the base is doped 10.sup.13 atoms/cc at the pn junction, increasing to 10.sup.16 atoms/cc in the drift field region. For p-conductivity type the base is doped 10.sup.16 at the junction, increasing to 10.sup.18 atoms/cc in the drift field. A back surface field is provided adjacent the ohmic contact (3) on the part of the base remote from the junction by doping to 10.sup.20 to 10.sup.21 atoms/cc. A passivating antireflective layer (30) is added to the light incident surface. The 1 micron emitter region (4) contains a 0.1 to 0.2 .mu.m thick high conducting region (5) adjacent the antireflective coating (30) on the light incident surface and a drift field region (7) 0.3 to 0.9 .mu.m thick. The base region (10) has a drift field region (9) 20 to 100 .mu.m thick and the overall base region (10) is 50 to 450 .mu.m thick. The back surface field region (12) is 1 .mu.m thick.

---

Inventors:	Hovel; Harold J. (Katonah, NY)
Family ID:	27397947
Appl. No.:	06/412,424
Filed:	August 30, 1982

---

Related U.S. Patent Documents

---

	Application Number	Filing Date	Patent Number	Issue Date
	229367	Jan 29, 1981
	968888	Dec 13, 1978
	101964	Dec 10, 1979

---

Current U.S. Class:	136/255; 136/261; 257/461
Current CPC Class:	H01L 31/068 (20130101); Y02E 10/547 (20130101)
Current International Class:	H01L 31/068 (20060101); H01L 31/06 (20060101); H01L 031/06 ()

* * * * *

---