Theoretical framework for performance evaluation of silicon quantum dot solar cell under low concentration illumination

Abstract

This article describes a silicon quantum dot (Si QD) solar cell with absorption enhancement due to quantum-confinement in the front-side emitter region, which helps in the improvement of the short-circuit current density. The Si QD solar cell is theoretically mimicked using an equivalent circuit to account the possible recombination losses under low concentration illumination. The electrical output is estimated using proposed theoretical model by considering the fundamental properties of intrinsic Si reported in the literature. An increase of ∼7.5% in generated current density is observed due to extra absorption of incident radiation through Si QD, which is in accordance with the experimental findings. The performance of Si QD/c-Si solar cell has been studied with respect to low concentration illumination, wherein with increasing CR from 1 sun to 5 suns, the short circuit current density increases from 29.4 to 147.2 mA/cm2 and the open circuit voltage increases from 0.565 to 0.609 V. This study provides a theoretical framework for design optimization of a future Si QD solar cells to achieve better performance of the device.