Numerical Simulation and Hole Transport Layers Optimization of a Lead Sulfide-Based Solar Cell with a Power Conversion Efficiency of Above 22%

Recently, the numerical simulation of solar cells has attracted tantamount scientific attention in the photovoltaic community because it saves on research time and resources before the actual fabrication of the devices in the laboratories. Despite significant advancements in the fabrication of quantum dot-sensitized solar cells (QDSSCs), the power conversion efficiency (PCE) is still low when compared to other solar cells such as perovskite. This efficiency gap poses a substantial challenge in harnessing the full potential of QDSSCs for widespread adoption in renewable energy applications. Enhancing the efficiency of QDSSCs is imperative for their commercial viability and widespread deployment. In this work, SCAPS-1D was used in the simulation of QDSSCs. The solar cell with a general configuration of FTO/TiO2/PbS/HTL/Au was investigated. In the device, PbS quantum dots were inserted as the absorber layer, TiO2 as the electron transport layer (ETL), gold as the back contact, and the following inorganic materials, i.e., copper (I) iodide (CuI), copper (I) oxide (Cu2O), cadmium zinc telluride selenide (CZTSe), copper iron tin sulfide (CFTS), and copper zinc tin sulfide selenide (CZTSSe) were tested as HTL materials, and FTO acted as the conductive substrate. The best HTL material (CZTSSe) exhibited a PCE of 22.61%, with a fill factor (FF) of 84.67%, an open circuit voltage (Voc) of 0.753 V, and a current density (Jsc) of 35.48 mA cm−2. This study contributes to the field by employing SCAPS-1D simulations to optimize QDSSCs, exploring novel inorganic HTL materials for these solar cells and identifying CZTSSe as a promising low-cost HTL that significantly enhances both the performance and commercial viability of QDSSCs.