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Zinc telluride (ZnTe) thin films have special semiconducting characteristics that make them very promising for a broad range of optoelectronic applications. In this work, a novel approach for synthesizing ZnTe thin films by spin coating technique is followed using a unique solution process with ZnTe directly dissolving in thiol-amine co-solvents. Thin films are synthesized on glass substrates and air annealed at 250-350 {\deg}C. The polycrystalline phase of ZnTe is revealed through the X-ray diffraction (XRD) study. The scanning electron microscopy (SEM) is used to observe the evolution of surface smoothness with annealing temperature. Moreover, elemental compositions of ZnTe thin film have been determined by energy dispersive spectroscopy (EDS) study. FTIR spectroscopy reveals that ZnTe has been successfully synthesized as confirmed by the characteristic peaks in the spectrum of 750-1000 cm-1. Optical properties of the ZnTe thin films have been investigated using UV-vis spectroscopy. The transmittance of the films increases with annealing temperature. Furthermore, the optical bandgaps of the films of 2.92, 2.84, and 2.5 eV have been found at 250, 300, and 350 {\deg}C annealing temperatures, respectively. These results suggest that controlling the annealing environment serves as a valuable strategy for tailoring the ZnTe film properties to meet specific application requirements. These results reveal that spin coated ZnTe thin films are attractive ones for various applications in optoelectronic devices such as solar cells and photodetectors., Comment: 23 pages, 6 figures, 1 table

The advanced multijunction solar cell (MJSC) has emerged as a frontrunner with higher efficiency in photovoltaic literature. It started its journey with a modest 20% efficient tandem solar cell, and today, it has reached an impressive 47.1% photoconversion efficiency (PCE) with six junction combinations. Since the early 1990s, these solar cells have been utilised for space applications. Recently, there has been a trend of using this genre for terrestrial applications as well. However, the complexity and high cost of the fabrication procedure have been the significant challenges over the last three decades. The photovoltaic (PV) community has witnessed a variety of fabrication approaches to address these hurdles. This paper reviews the progression of computational and experimental research approaches of III-V MJSCs and their fabrication processes. In addition, it addresses the barriers hindering the progress of these cells and their prospects. This review gathers insights from a handful number of articles on III-V MJSCs to provide a comprehensive guide for the new entrants, experts and practitioners about the research methodologies, growth techniques, current status, challenges, and opportunities in a timely and conscious manner., Comment: 17 pages, 4 figures

In this article, we demonstrate CdSe-CuSbSe2-based double junction two-terminal tandem solar cells simulated with SCAPS-1D. The highest performance of the tandem cell has been confirmed by optimizing the electrical and optical properties of window, top absorber, CdSe (bandgap 1.7 eV), bottom absorber, CuSbSe2 (bandgap 1.08 eV) and back surface layers. In addition, the effect of different parameters such as thickness, doping, defect density of different layers has been investigated in details. With the optimized condition, the modeled CdSe-CuSbSe2 double-junction two-terminal tandem solar cell displays the noticeable efficiency of 42.64% with open circuit voltage of 2.09 V, short circuit current density of 24.09 mA/cm2 and fill factor of 84.36%, respectively. These results are highly propitious for the construction of all-chalcogenide based high performance tandem photovoltaic cells in the future., Comment: 26 pages, 9 Figures, 1 Table

Ternary chalcostibite copper antimony selenide (CuSbSe2) is a promising absorber material for next generation thin film solar cells due to the non-toxic nature, earth-abundance, low-cost fabrication technique, optimum bandgap and high optical absorption coefficient of CuSbSe2. Conventional single heterojunction CuSbSe2 solar cells suffer from high recombination rate at the interfaces and the presence of a Schottky barrier at the back contact, which limit their power conversion efficiencies (PCEs). In this study, we propose a dual-heterojunction n-ZnSe/p-CuSbSe2/p+-CGS solar cell, having copper gallium selenide (CGS) as the back surface field (BSF) layer. The BSF layer absorbs longer wavelength photons through a tail-states-assisted (TSA) two-step upconversion process, leading to enhanced conversion efficiency. Numerical simulations were carried out using SCAPS-1D to investigate the performance of the proposed solar cell with respect to absorber layer thickness, doping concentrations and defect densities. The simulation results exhibit PCE as high as 43.77% for the dual-heterojunction solar cell as compared to 27.74% for the single heterojunction n-ZnSe/p-CuSbSe2 counterpart. The dual-heterojunction structure has, therefore, the potential to approach the Shockley-Queisser (SQ) detailed balance limit and can lead to extremely high PCEs in emerging thin film solar cells., Comment: 21 pages, 7 figures, 2 tables