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 quantumefficiency takes a uniform doping concentration in each layer into consideration. The theoretical treatment aims toinvestigate the effect of device parameters on the efficiency. Three different cases of the incident light wavelengthshave been considered; short wavelengths, medium wavelengths, and long wavelengths. There is no wavelength rangebetween them, but when the most of the incident light (about 63% or more) absorbed near the surface, it is calledshort wavelength, and when most of the light absorbed in υ-layer, it is called medium wavelength else called longwavelength.A high quantum efficiency at the wavelength of interest, combine with its low operating voltage andcapability, make this detector a promising for use in communication systems and computer interconnections.Highspeed silicon p-υ-n photodetector operates at 700 nmwavelength is reported. By using a reverse bias voltage tocontrol υ-layer width, a 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 widthof the υ-layer and biasing voltage. The results are achieved with the aid of MATLAB programming tool version8.1.0.604 R2013a.