Investigation on indium concentration in two-terminal tandem indium gallium nitride solar cells by SCAPS-1D

Indium gallium nitride (InGaN) thin-film solar cell is a promising photovoltaic (PV) device. InGaN’s bandgap is tunable from 0.7 to 3.4 eV and it exhibits a high absorption coefficient exceeding 10 5 cm −1 . Besides, InGaN solar cells can be used in tandem configuration, to effectively absorb the solar spectrum. Previous works found that increased indium (In) concentration leads to inverse relationship between open-circuit voltage (Voc) and power conversion efficiency (PCE) of the solar cell. This leads to deleterious device performance. This study aims to assess the performance of two-terminal InGaN tandem solar cells using SCAPS-1D simulation software. The findings revealed maximum short-circuit current density (J sc ) of 26.19 mA cm −2 , open-circuit voltage (V oc ) of 2.13 V, fill factor (FF) of 89.68%, and PCE of 30.17% from the tandem device. The results indicate that higher In concentration enhances light absorption and the overall PCE, with tandem cells outperforming single-junction cells. This study makes a valuable contribution to the advancement of high-efficiency solar technology based on InGaN.