Title:
Rapid Photo-Assisted Forming Gas Anneal (FGA) for High Quality Screen-Printed Contacts for Silicon Solar Cells
Rapid Photo-Assisted Forming Gas Anneal (FGA) for High Quality Screen-Printed Contacts for Silicon Solar Cells
Author(s)
Ebong, Abasifreke
Hilali, Mohamed M.
Rohatgi, Ajeet
Hilali, Mohamed M.
Rohatgi, Ajeet
Advisor(s)
Editor(s)
Collections
Supplementary to
Permanent Link
Abstract
Formation of low-cost high-quality contacts is the key to cost-effective silicon solar cells. Screen-printing is widely used in Industry because it is simple, low-cost and rapid. However, cost and throughput gains are attained at the expense of performance. Fill factors of most commercial cells are in the range of 0.68-75 for single crystalline
material. This paper shows that a rapid 400°C/0.5-3 min photo-assisted anneal in a forming gas ambient can raise the fill factor (FF) of screen-printed (SP) single and multicrystalline (mc) Si cells from - 0.70 to - 0.77 and 0.76, respectively. Dark I-V analysis showed that this results
from a decrease in series resistance by a factor of 2 to 4. Thus initial belt firing conditions can be tailored (~ 700DC)
to first prevent the junction shunting, which generally results in high series resistance (Rs), and then the rapid
photo-assisted anneal in forming gas ambient can be used to reduce the resistive losses for achieving high FF without much junction shunting. The LBIC analysis on multicrystalline silicon shows that a 30-second forming gas anneal in RTP not only reduces the glass frit at the silicon/silver interface but also enhances hydrogenation of
bulk defects.
Sponsor
Date Issued
2000-09
Extent
Resource Type
Text
Resource Subtype
Proceedings