ZnO as an anti-reflective layer for GaAs based heterojunction solar cell

Currently, how to improve the efficiency of solar cells has attracted wide attention. ZnO film is one of the most effective films today, which can act as both emitter and anti-reflective coating of solar cells. In this paper, n-type ZnO/p-type GaAs solar cell is modeled by analyzing the band edge discontinuities, electric field distributions at the ZnO/GaAs interface and cell parameters with varying ZnO layer thickness, affinity values and carrier concentration. Moreover, in order to improve the band offset alignment at the heterojunction, Mg doped ZnO emitter is a possible alternative. Then, the thickness and carrier concentration of MgZnO emitter layer are studied and simulation results show stronger electric field, better fill factor and higher efficiency. After optimization of two solar cells by using Silvaco Atlas, it is observed that the conversion efficiencies of ZnO/GaAs and MgZnO/GaAs solar cells are 22.84% and 23.44% respectively.

Automated summary

This study models the n-type ZnO/p-type GaAs solar cell by analyzing different parameters and discusses the potential of Mg doped ZnO emitter to improve efficiency. After optimization using Silvaco Atlas, simulation results show that MgZnO/GaAs solar cell has a higher conversion efficiency.