Photocurrents Mechanisms and Performance Considerations of a Reach Through P+-N-N+ Silicon Photodiode

Abstract

The proposed model is a reverse-biased p+-n-n+ silicon photodiode which offers good quantum efficiency and high response speed suitable for photodetectors application. The theoretical analysis of the device is started with the evaluation of the built-in, reach through, and breakdown voltages. Photocurrent mechanisms and theoretical treatment in each layer of the device are modeled. The effect of the surface recombination velocity and the absorption coefficient on the minority carries distribution in each layer within the device and on the overall device performance is presented. An effective and powerful modeling process of the mathematical foundations of the photodiode is performed with the aid of MATLAB R2008a version 6.5A. It is found that for a low reach through voltage, the concentration of the n layer should be reduced, the photocurrents increase as the width of the P+ and n layer increases at a relatively low surface recombination velocity and better absorption coefficient.