Simulation of InGaN p–i–n double heterojunction solar cells with linearly graded layers

This paper deals with theoretical investigation of the performance of nonpolar InGaN double heterojunction solar cell. Inserting linearly graded layers at the interface between the p-GaN/i-InGaN and i-InGaN/n-GaN is shown to remove the barrier for electron and hole transport into GaN and increases the cell efficiency. The proposed structure is simulated using 1D finite element method. The influence of the graded layer thickness on the conversion efficiency is particularly investigated. The results show that the efficiency can be optimized by choosing an appropriate graded layer thickness. Simulations predict a conversion efficiency of about 24% for a graded layer thickness of 0.15 μm.