N-Face Semi-Bulk Absorber Boosts Conversion Efficiency of InGaN Solar Cell

The purpose of this paper is to investigate the N-face InGaN semi-bulk as a solution to achieve a high-efficiency solar cell based on III-nitride materials, which could mitigate the issues of both InGaN crystalline quality and charge polarization. Simulation of both InGaN bulk and semi-bulk with both N and Ga faces, using an analytical model, shows that this approach leads to a significant increase of the power conversion efficiency. It is found that the conversion efficiency of the new solar cell structure with 25% indium content is about three times larger than the one based on the fully relaxed bulk InGaN absorber (no detrimental effect of the polarization effect) with the same indium concentration. This approach could thus be beneficial to the realization of efficient InGaN-based solar cells.