Experimental study of the factors governing the Staebler-Wronski photodegradation effect in a-Si:H solar cells. Annual subcontract report, 1 March 1994--31 March 1995

This report describes continuing experiments on electroluminescence (EL) and transient forward bias current (TFC) as well as photocurrent before and after light soaking for amorphous silicon (a-Si:H) devices. we continued our EL spectrum analysis on a p-i-n device with and without SiC:H buffer in the p-i interface. We started a program to study the Staebler-Wronski effect (SWE) in p-i-n solar cells made with and without H{sub 2} dilution, in collaboration with Solarex. In collaboration with L.E. McNeil, we studied the carrier recombination in p-i-n cells by both photoluminescence and EL. In collaboration with G.J. Adriaessens at Catholic University Leuven, Belgium, we studied TFC in p-i-n devices. In collaboration with Y. Wu, we studied the local Si-H bonding configuration in hot-wire samples by nuclear magnetic resonance. We concentrated on determining the factors controlling SWE, and on determining the correlation of EL data to the cell structure or preparation conditions, such as the effects of buffering and H{sub 2} dilution, by EL measurements