Controlling hydrogen contents and bond configurations for high-quality and high-reliability a-Si films

Abstract

We previously reported that a reduction of SiH 2 bond density in the i-layer effectively prevents light-induced degradation of a-Si solar cells. For further reduction of SiH 2 bond density, we fabricate a-Si films at higher substrate temperature (Ts:250 ∼ 400°C) with a glow discharge method by using super chamber. SiH 2 bond density can be reduced to about 10 20cm −3, and highly photoconductive and stable a-Si films are obtained. As a new attempt to reduce SiH 2 bond density, we have investigated an ion-gun CVD method. Hydrogen bond configurations are found to be strongly affected by the accelerating voltage of ions.