Dependence of the Property of InGaN p-i-n Solar Cells on the Light Concentration and Temperature

The effects of the light concentration and temperature on the performance of InGaN p-i-n homojunction solar cells were investigated experimentally. With the increase in the light concentration, the short-circuit current density J_sc increases linearly, and the open-circuit voltage V_oc increases logarithmically. However, the fill factor FF and the relative efficiency η increase first and then decrease. On the other hand, the performance of the solar cell becomes worse with the increase in temperature. The temperature coefficients of important parameters related with the cell property were discussed. The red shift of the peak external quantum efficiencies was observed with increasing temperature due to the band-gap shrinkage. In addition, the ideality factor n and the reverse saturation current density J_s were also investigated to reveal the intrinsic mechanism of temperature dependence and the effect of crystalline quality. This paper provides the variation trends of device characteristics, which are useful references concerning the reliability of GaN-based solar cells.