Effect of band alignment on the n-InAlN/p-Si heterojunction for solar cells: a numerical study

Abstract

The Inx Al1-xN heterojunction exhibits interesting features that make it a promising candidate for designing solar cells. Nevertheless, there are no studies about how the three types of band alignment (straddled, staggered and broken gap) affect the Inx Al1-x N heterojunction. In this work, Inx Al1-x N on commercial p-type silicon heterojunction was studied using computational simulation in solar cells. The main objective was to study the band alignment to maximize the efficiency of the cell for building experimental devices in the future. The thickness of the silicon layer remained constant at 500 μm. The thickness of Inx Al1-x N was varied between 10 nm and 100 nm, and the concentration of InN between 20% and 90%. It was found that the band alignment impacted on the open circuit voltage, the short circuit current density, the efficiency of the solar cell, and the quantum efficiency. It is theoretically concluded that a n-Inx Al1-x N/p-Si type heterojunction solar cell can be designed, with a maximum efficiency of 26.6%, adjusting the thickness of the InAlN layer to 10 nm and the InN concentration of 70%. This valuable result shows a good prospect for the manufacture of experimental devices.