Design and Simulation of a High‐Efficiency CuInS2 Thin‐Film Solar Cell with a Thin CIS Current Augmenter

Abstract

Ternary chalcopyrite compound cupper indium disulfide (CuInS2)‐based photovoltaic cells are designed and numerically computed. In this design, n‐CdS and p++‐MoS2 have been used as window and back surface field (BSF) layers, respectively. The modeled n‐CdS/p‐CuInS2/p++‐MoS2 device provides power conversion efficiency (PCE) of 24.6% with JSC of 26.98 mA cm−2, VOC of 1.05 V, and fill factor (FF) of 86.93%. This efficiency is ≈60% higher the than n‐CdS/p‐CuInS2 single heterostructure. Furthermore, the use of a second CuInSe2 (CIS) absorber layer between CuInS2 absorber and MoS2 BSF layer significantly enhances the short‐circuit current. As a result, the current expressively improves to 38.48 mA cm−2, yielding an efficiency of 32.4%. The greater built‐in potential in absorber/BSF interface is attributed to the high JSC and VOC, causing the increment of efficiency. Besides, the photon management by Bragg reflector with 90% back and front reflectance recycling effect further increases the PCE to 36.1%. This work indicates the prospects of CuInS2 solar cells with a CuInSe2 current augmenter and MoS2 BSF layers for the fabrication of efficient CuInS2 solar cells.