Effect of Composition on the Properties of Amorphous Silicon Carbide at a Certain Optical Gap

Publisher Website
Google Scholar
Abstract
The relationship between composition and optoelectric properties was investigated for a-SiC:H alloys with a constant optical gap (E opt) and different compositions. The compositions, hydrogen content (C H) and carbon content (C C), and the optical gap of a-SiC:H were successfully controlled independently. E opt of a-SiC:H can be expressed by a linear function of the compositions and a negative dependence of E opt on C C is observed for our samples. In the constant E opt system, C H increases with an increase in C C in spite of a rise in the substrate temperature. In particular, the increase in the Si–H2 density is much more significant than that in the C–H bond density. This result suggests that the incorporated carbon atoms affect the bonding configuration between silicon and hydrogen. The film properties, such as photoconductivity and defect density, and solar cell performance become inferior both before and after light-soaking with an increase in C C, namely the Si–H2 density. The Si–H2 bond is an important factor to consider when determining the stability of a-SiC:H as well as a-Si:H and a-SiGe:H.