In an Sb₂Se₃-based solar cell, the buffer layer is sandwiched between the absorber and the window layer, playing an essential role in interfacial electricity. Generally, CdS is used as a buffer layer, but its toxic nature and low bandgap can cause current loss because of parasitic absorption. In this work, we optimized the buffer layer by using ZnS as an alternative to the CdS buffer layer in order to decrease the use of CdS. The effect of different buffer layers on the solar device was explored by numerical simulation with the help of SCAPS 1D software. The basic parameters, such as open-circuit voltage (Voc), current density (Jsc), fill factor (FF), and efficiency (η) were analyzed and compared for both the buffer layers (CdS/ZnS). The results demonstrate that changing buffer materials and thicknesses has a significant impact on cell performance. The efficiency for the ZnS buffer layer was lower compared to that of the CdS-based solar cells because of insufficient energy band alignment. In order to enhance the efficiency of Sb₂Se₃-based solar cells, we used CdS/ZnS dual buffer layers and studied the device performance. The work function of the back contact also affects the device performance, and for work functions below 4.8 eV, the device’s efficiency was very low. The effect of varying the thicknesses and temperatures of the buffer layers on the I-V/C-V characteristics, quantum efficiency, and energy band structure are also reported. This study shall guide the researcher in reducing CdS and improving the device’s performance.

Perovskite-based solar cells (PSCs) have recently gained much attention due to their distinctive optical and electrical properties. Cesium titanium fluoride (Cs₂TiF₆) is an example of lead-free perovskite absorber material with a bandgap of 1.9 eV, making it suitable for a solar device. However, the high cost of the hole transport material (HTM) and other considerations prevent their commercial production. Antimony selenide (Sb₂Se₃) is well suited for HTM as it is low-cost material with a tunable bandgap. The work presents the TiO₂/Cs₂TiF₆/Sb₂Se₃-based solar cell performance using SCAPS-1D simulation software. The effect of all the active layer thicknesses, defect density, hole-electron mobility, and temperature on the device is also simulated. I–V, C–V, and QE curves and energy band diagrams show the photovoltaic device's excellent performance. The outputs are competent enough with an efficiency of 22.10 % when Sb₂Se₃ is used as a hole transport layer (HTL) in the device architecture. The results suggest that the lead-free solar cell is a promising future option for the solar cell community regarding environmental friendliness and high efficiency.

Thin-film solar cells are simple and affordable to produce, but their efficiency is low compared to crystalline-silicon solar cells, and needs to be improved. This study investigates the photovoltaic performance of different absorber materials (CdTe, CIGS, Sb₂Se_3, and CZTS) with simple structure Au/absorber/CdS/ITO. The research uses the SCAPS (Solar Cell Capacitance Simulator), a mathematical model based on Poisson and continuity equations. The impact of various parameters on cell performance, such as absorber layer thickness, acceptor density, electron affinity, back contact work function, and temperature, are examined. As per the simulation results, an absorber thickness of 4 µm is suitable for achieving the maximum efficiency for all the absorber materials. The optimized acceptor density for CdTe/CIGS/ Sb₂Se₃ and CZTS is taken as 10¹⁶ cm⁻³ and 10¹⁷ cm⁻³, respectively. The back contact work function and device temperature were set to be 5.1 eV and 300 K, respectively, to achieve excellent performance. Among all the absorber materials, the highest efficiency of 28.2% was achieved for CZTS. The aim is to highlight the various absorber layers’ performances by optimizing the device parameters. The obtained results can be used in solar energy harvesting applications due to the improved performance characteristics.