The controlled and efficient formation of oxygen vacancies on the surface of metal oxide semiconductors is required for their use in gas sensors. This work addresses the gas-sensing behaviour of tin oxide (SnO₂) nanoparticles for nitrogen oxide (NO₂), NH₃, CO, and H₂S detection at various temperatures. Synthesis of SnO₂ powder and deposition of SnO₂ film is conducted using sol-gel and spin-coating methods, respectively, as these methods are cost-effective and easy to handle. The structural, morphological, and optoelectrical properties of nanocrystalline SnO₂ films were studied using XRD, SEM, and UV-visible characterizations. The gas sensitivity of the film was tested by a two-probe resistivity measurement device, showing a better response for the NO₂ and outstanding low-concentration detection capacity (down to 0.5 ppm). The anomalous relationship between specific surface area and gas-sensing performance indicates the SnO₂ surface’s higher oxygen vacancies. The sensor depicts a high sensitivity at 2 ppm for NO₂ with response and recovery times of 184 s and 432 s, respectively, at room temperature. The result demonstrates that oxygen vacancies can significantly improve the gas-sensing capability of metal oxide semiconductors.

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.

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.

As a promising solar absorber material, antimony selenide (Sb₂Se₃) has gained popularity. However, a lack of knowledge regarding material and device physics has slowed the rapid growth of Sb₂Se₃-based devices. This study compares the experimental and computational analysis of the photovoltaic performance of Sb₂Se₃-/CdS-based solar cells. We construct a specific device that may be produced in any lab using the thermal evaporation technique. Experimentally, efficiency is improved from 0.96% to 1.36% by varying the absorber’s thickness. Experimental information on Sb₂Se₃, such as the band gap and thickness, is used in the simulation to check the performance of the device after the optimization of various other parameters, including the series and shunt resistance, and a theoretical maximum efficiency of 4.42% is achieved. Further, the device’s efficiency is improved to 11.27% by optimizing the various parameters of the active layer. It thus is demonstrated that the band gap and thickness of active layers strongly affect the overall performance of a photovoltaic device.

Antimony selenide (Sb₂Se₃) material has been brought into sharp focus in the solar cell field due to its remarkable performance in recent times. Solar cell efficiency increases daily because of the excellent properties of Sb₂Se₃ material and progressive optimisation of each layer, especially the hole-transporting layer (HTL); it suppresses the recombination of the back surface and increases the built-in potential and efficiency. In this work, we used Sb₂Se₃ as an absorber layer and compared the behaviour of typical hole transport materials (HTMs) (Spiro-OMeTAD, CuSCN, and CuI) and their influence on device performance. The Sb₂Se₃ photovoltaic model with different HTMs was studied by SCAPS (version 3.3.10) software. Efficiency is highly influenced by light source and intensity. Thickness and defect density of the Sb₂Se₃ layer, the work function of the back contact, and series and shunt resistances also play an essential role in the better execution of solar cells. The performance of the device is enhanced when the transmission percentage increases at the front contact. The metalwork function must be 5 eV to attain a highly efficient PV cell, and after optimisation, CuI is the best HTM with a 23.48% efficiency.