Photoresponse of a Highly-Rectifying 3C-SiC/Si Heterostructure Under UV and Visible Illuminations

Abstract

In this letter, we report the photo-characteristics of an n-3C-Silicon carbide (SiC)/p-Si heterojunction under ultraviolet (UV) and visible illuminations. The 3C-SiC thin film has been grown on Si (100) substrate by a low pressure chemical vapor deposition technique at 1000 °C. The as-grown structure shows an excellent rectification ratio ( ${I}_{F}/{I}_{R}$ ) of $1.8\times 10^{6}$ at ±2 V and a reverse bias current of ${5.5}\times {10}^{-9}$ A at 2V in dark conditions. The heterojunction exhibits good sensitivity simultaneously to both UV (375 nm) and visible (637 nm) illuminations. The results indicate that the fabricated structure could be an excellent platform where detection of a wide spectral illumination is vital. The insight of electron-hole pairs generation and carrier transport mechanism at different illumination conditions is explained in detail via an anisotype heterojunction energy band diagram.