Effect of hydrogen dilution on the structure of amorphous silicon alloys

Abstract

We investigate why high levels of hydrogen dilution of the process gas lead to enhanced light soaking stability of amorphous silicon $\mathrm{(a}\mathrm{-Si}$ ) alloy solar cells by studying the microstructural properties of the material using high-resolution transmission electron microscopy (TEM) and Raman spectroscopy. The TEM results show that $a\mathrm{-Si}$ alloy (with or without hydrogen dilution) is a heterogeneous mixture of amorphous network and linear-like objects that show evidence of order along their length. The volume fraction of these ordered regions increases with increasing hydrogen dilution.