QUANTUM EFFICIENCY OF A p-υ-n Si PHOTODETECTOR

Abstract

The quantum efficiency of a silicon p-υ-n photodetector is present. The analysis to obtain the quantum efficiency takes a uniform doping concentration in each layer into consideration. The theoretical treatment aims to investigate the effect of device parameters on efficiency. Three different cases of incident light wavelengths have been considered; short wavelengths, medium wavelengths, and long wavelengths. There is no wavelength range between them, but when most of the incident light (about 63% or more) is absorbed near the surface, it is called short wavelength, and when most of the light is absorbed in the υ-layer, it is called medium wavelength else called long-wavelength. A high quantum efficiency at the wavelength of interest, combined with its low operating voltage and capability, makes this detector promising for use in communication systems and computer interconnections. Highspeed silicon p-υ-n photodetector operates at 700 nm wavelength is reported. By using a reverse bias voltage control υ-layer width, the high quantum efficiency of 80% is attained corresponding to υ-layer width of 5.36 mand biasing voltage of 2.182 V.The results showed that the quantum efficiency is directly proportional to the width of the υ-layer and biasing voltage. The results are achieved with the aid of MATLAB programming tool version8.1.0.604 (R2013a).