Formation of high quality screen-printed contacts to homogeneous high sheet resistance emitters (HHSE)

Author

Ebong, A. ; Cooper, I.B. ; Rounsaville, B.C. ; Zimbardi, F. ; Upadhyaya, A. ; Rohatgi, A. ; Borland, W. ; Mikeska, K. ; Carroll, A.

Author_Institution

Dept. of Electr. & Comput. Eng., Univ. of North Carolina at Charlotte, Charlotte, NC, USA

fYear

2011

fDate

19-24 June 2011

Abstract

In this paper we report on the formation of high quality contacts to HHSE with a sheet resistance variation of ≥30 Ω/sq using a commercial front-side Ag paste, PV16A from DuPont. We fabricated and characterized solar cells with emitter sheet resistances of 65, 75, 85, 95 and 105 Ω/sq. We found that emitter sheet resistances in the range of 65-95 Ω/sq can be contacted with low average series resistance of 0.63-0.77 Ω-cm² and high fill factor (FF) of 77.4-78.8%. The 75 Ω/sq emitter gave the best average efficiency of 18.3%, followed by 18.2% for the 65 Ω/sq, 18.0% for the 85 Ω/sq, and finally 17.7% for the 95 Ω/sq. The 105 Ω/sq emitter gave a low FF due to high series resistance, but the shunt resistance and ideality factor were excellent, which suggests the paste was not encroaching the shallow emitter junction.

Keywords

electrical contacts; printing; solar cells; FF; PV16A; average series resistance; commercial front-side paste; efficiency 17.7 percent; efficiency 18.0 percent; efficiency 18.2 percent; efficiency 18.3 percent; fill factor; high quality screen-printed contact formation; homogeneous HHSE; homogeneous high sheet resistance emitter; ideality factor; shallow emitter junction; shunt resistance; solar cell; Contact resistance; Electrical resistance measurement; Photovoltaic cells; Silicon; Surface resistance; Surface waves;

fLanguage

English

Publisher

ieee

Conference_Titel

Photovoltaic Specialists Conference (PVSC), 2011 37th IEEE

Conference_Location

Seattle, WA

ISSN

0160-8371

Print_ISBN

978-1-4244-9966-3

Type

conf

DOI

10.1109/PVSC.2011.6186382

Filename

6186382