Enhancement of Short-Circuit Current Density in Superlattice-Based InGaN/GaN Solar Cells

Abstract

In this paper, the mechanism of short-circuit current density (JSC) enhancement in InGaN/GaN superlattices(SLs)-structured solar cells (SCs) is investigated theoretically and experimentally, and compared with conventional InGaN/GaN multiple quantum wells (MQWs) SCs. Due to the ultrathin structure of the X-ray diffraction SLs, a tunneling model is introduced in Silvaco software. The simulation results show that the trend of the simulation results is consistent with the experimental values. Due to the contribution of the tunneling effect, the JSC of SCs with SLs structure is greatly improved, but the open circuit voltage (VOC) is also reduced due to defects in the growth process of epitaxial wafers with SLs structure. These observations suggest that tunneling effects increase the JSC of the SCs, thus improving the photovoltaic conversion efficiency (PCE) of SCs. This study provides evidence for the fabrication of highly efficient InGaN SCs.