Silicon Solar Cell Space Charge Region and Capacitance Behavior under Electric Field

Bernard Zouma,Fabé Idrissa Barro,Prince Abdoul Aziz Honadia

doi:10.4236/epe.2021.131003

Abstract

This paper investigates theoretically the behavior of the space charge region of a silicon solar cell and its associated capacitance under the effect of an external electric field. The purpose of this work is to show that under illumination the solar cell’s space charge region width varies with both operating point and the external induced electric field and how the solar cell capacitance varies with the space charge region width. Based on a 1D modelling of the quasi-neutral p-base, the space charge region width is determined and the associated capacitance is calculated taking into account the external electric field and the junction dynamic velocity. Based on the above calculations and simulations conducted with Mathcad, we confirmed the linear dependence of the inverse capacitance with space charge region width for thin space charge region and we exhibit an exponential dependence for large space charge region.

Highlights

The p-n junction remains the core of semiconductor devices; the device performance and behavior are related directly to those of this p-n junction
Based on the above calculations and simulations conducted with Mathcad, we confirmed the linear dependence of the inverse capacitance with space charge region width for thin space charge region and we exhibit an exponential dependence for large space charge region
The aim of this paper is to analyze the behavior of the space charge region and the capacitance of a forward biased silicon solar cell on the one hand, and, on the other, the relationship between the capacitance and the space charge region width for various polarization induced electric fields

Summary

Introduction

The p-n junction remains the core of semiconductor devices; the device performance and behavior are related directly to those of this p-n junction. Among many parameters that influence the operation of the p-n junction, the injection level plays a very important role [1] [2] [3] [4]. The space charge region and the total capacitance can characterize the p-n junction [6]. This capacitance is of major importance in switching circuits: photovoltaic power plant with DC/AC power converters or switching regulators [7] [8] where the needs are to move or remove an amount of charge as fast as possible and testing modules under flash illumination [9] [10]

Objectives

Results

Conclusion