Bandgap narrowing effects on the open circuit voltage in Si, GaAs and InP solar cells

Abstract

Bandgap narrowing affects semiconductor device operation. Solar cells are pn junction devices for which the energy bandgap is a very important parameter. The aim of this paper is to investigate how bandgap narrowing can influence the open circuit voltage of silicon, gallium arsenide and indium phosphide solar cells. The increase in the base doping concentration for improving device operation is limited by bandgap narrowing effects. A quantitative study of the open circuit variation with base doping concentration and ideality factor is presented and the critical values for these parameters are determined for these materials.