Optoelectronic Properties of Hydrogenated Amorphous Substoichiometric Silicon Carbide with Low Carbon Content Deposited on Semi‐Transparent Boron‐Doped Diamond

Abstract

Hydrogenated amorphous substoichiometric silicon carbide (a‐Si1−xCx:H, x < 0,1) thin films and diodes with low carbon content are prepared from a mixture of H2, SiH4, and CH4 by plasma‐enhanced chemical vapor deposition at a relatively high temperature of 400 °C on semi‐transparent boron‐doped nanocrystalline diamond (B‐NCD) electrodes with an underlying Ti grid. Vibration spectra indicate that CH4 prevents Si crystallization at elevated deposition temperatures and confirm an increasing carbon content up to x = 0.1 for samples grown with SiH4/CH4 flows up to 1:3. Dark current–voltage characteristics of B‐NCD/a‐Si1−xCx:H diodes show a rectifying ratio of about four orders at ±1 V. However, under white light illumination, an energy conversion efficiency of 4% is limited by a high serial resistivity of the B‐NCD electrode and S‐shaped photocurrent near the open‐circuit voltage.