Defects in amorphous silicon carbide and their relation to solar cell device performance

摘要

Amorphous silicon carbide alloys are being investigated as a possible top photovoltaic layer in photoelectochemical (PEC) cells used for water splitting. In order to be used as such, it is important that the effect that varying carbon concentration has on bonding, and thus the electronic and optical properties, is well understood. The samples being studied are silicon rich films with between 6 and 11 atomic percent of carbon. Electron spin resonance (ESR) experiments, including light-induced ESR (LESR), were performed to study defects from dangling bonds which occur dominantly at the silicon atoms in these films. Spin densities resulting from silicon dangling bonds varied between 10~(16) and 10~(17) spins/cm~3. Lastly, to test the validity of these materials being used for devices we prepared pin structured solar cells with the films being studied used as the absorber layer.