Characteristics of a single a-SiC : H/a-Si : H heterostructure as a high-gain photodetector

Abstract

This paper describes a structure for the hydrogenated amorphous-silicon (a-Si : H) based photodetector having high optical gain. This structure consists of a single heterostructure of hydrogenated amorphous-silicon carbide (a-SiC : H) and a-Si : H. The operation of this photodetector is based on the multiplication of the photoinduced carriers in a-SiC : H layer. the photocurrent multiplication is dependent on the optical band-gap of the a-SiC : H used, and with the use of 2.35 eV a-SiC : H, its multiplication is reached to 9 at the bias voltage of 20. The leakage current and the response-speed of this photodetector were also less than 10 nA/cm 2 and 0.5 μs, respectively, under the reverse-bias of 20 V.