Browsing by Author "Haque M.M."

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    Growth and characterization of Bi2Te2.70Se0.30 nanostructured materials by using a cost-effective chemical solution route
    (Elsevier B.V., 2023) Bhuiyan M.R.A.; Korucu H.; Mamur H.; Haque M.M.
    A chemical solution route was employed to successfully synthesize single-phase Bi2Te2.70Se0.30 nanostructured powders at room temperature, ensuring minimal contamination. The synthesized powders underwent a comprehensive analysis using a range of characterization techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive analysis of X-ray (EDAX), ultraviolet-visible (UV) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, atomic-force microscopy (AFM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The temperature-dependent behaviors of electrical conductivity and the Seebeck coefficient were also explored. The findings revealed that the synthesized powders displayed consistent spherical morphology, with an average diameter of 68.42 nm. Additionally, they exhibited a band gap energy of 0.615 eV. This research highlights the significant improvement achieved by incorporating selenium into the Bi2Te2.70Se0.30 materials through this synthesis process. The EDAX analysis confirmed the stoichiometric atomic ratio of bismuth (Bi), tellurium (Te), and selenium (Se) elements. Furthermore, the TEM images revealed the presence of agglomeration within the powders, demonstrating a primary crystalline size characterized by relatively small dimensions. The emergence of a pronounced exothermic peak at around 650 K signaled the commencement of oxidation for the Bi2Te2.70Se0.30 material. In electrical measurement, a synergy was achieved between heightened electrical conductivity and a well-matched Seebeck coefficient, with the goal of enhancing energy conversion efficiency in TE applications. These findings demonstrate the potential of the synthesized powders for producing nanostructured thermoelectric (TE) materials with controlled grain sizes, which are essential for the fabrication of high-performance thermoelectric generators (TEGs). © 2023 The Authors
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    Effect of various layers on improving the photovoltaic efficiency of Al/ZnO/CdS/CdTe/Cu2O/Ni solar cells
    (Elsevier B.V., 2023) Hosen R.; Sikder S.; Uddin M.S.; Haque M.M.; Mamur H.; Bhuiyan M.R.A.
    The photovoltaic (PV) cell structure containing Al/ZnO/CdS/CdTe/Cu2O/Ni has been simulated using the SCAPS-1D software. The PV device includes a zinc oxide (ZnO) transparent conductive oxide (TCO) window layer, a cadmium sulfide (CdS) buffer layer, and a cadmium telluride (CdTe) absorber layer. Additionally, an electron reflected-hole transport layer (ER-HTL) comprising cuprous oxide (Cu2O) is introduced between the absorber layer and the back metal contact. Aluminum (Al) and nickel (Ni) serve as the upper/top and back contact materials, respectively, interconnecting the layers. The back contact materials, the thickness of the absorber, buffer, and window layers, the acceptor density of the absorber layer, the donor density of the buffer layer, the series and shunt resistance, as well as temperature, were all modified to investigate the PV performance of this structure. The PV performance parameters are evaluated through the open-circuit voltage (VOC), short-circuit current (JSC), fill factor (FF), and power conversion efficiency (PCE). To achieve optimal performance, it is recommended to set the acceptor and donor densities for the absorber and buffer layers at 1017 cm−3. These desired densities can be attained by using a window and buffer layer thickness of 100 nm, an absorber layer thickness of 2500 nm, and an ER-HTL of 50 nm. The optimized model demonstrates PV performance characteristics of 1.4811 V for VOC, 28.682434 mA/cm2 for JSC, 74.91 % for FF, and 31.82 % for PCE under the AM 1.5 G spectrum. Furthermore, it exhibits a quantum efficiency of around 100 % at visible wavelengths. © 2023 The Authors
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    Optimizing the performance of Bi2Te3 TECs through numerical simulations using COMSOL multiphysics
    (Elsevier B.V., 2024) Hasan M.K.; Haque M.M.; Üstüner M.A.; Mamur H.; Bhuiyan M.R.A.
    Manufacturers need to determine the best geometries for thermoelectric coolers (TECs) to achieve optimal performance. In this study, we employed the COMSOL Multiphysics software to simulate the performance enhancement of Bi2Te3 TEC. The TEC is constructed with alumina (Al2O3), copper (Cu), and bismuth telluride (Bi2Te3) materials. In particular, Al2O3 acts as an electric insulator for the top and bottom layers, Cu functions as a conductor, and Bi2Te3 serves as the p- and n-type thermoelectric (TE) legs between the Cu layers. The study examined how different TE leg heights (1.5 mm, 2 mm, and 2.5 mm) and shapes (square and rectangular) affected the TEC's performance. It looked at various factors, such as temperature gradient, electric potential, normalized current density, and total net energy rate. Additionally, the thickness effects of the insulator, conductor, and the TE leg pitch of the TEC have also been investigated. According to the obtained results, it has been determined that the square type of leg geometry has provided the best performance among the tested geometries, and it has been recommended that its leg geometry be 1.00 mm × 1.00 mm × 1.5 mm, the thickness be 0.375 mm for Al2O3 and 0.125 mm for Cu, and the pitch be 0.50 mm, as they are expected to yield satisfactory performance. The research study involved obtaining performance parameters for 18 TE elements utilized in the fabrication of TEC. The TEC-simulated results revealed the following performance metrics: ΔTmax = 73.94 K, Umax = 2.52 V, Imax = 3.00 A, Qmax = 4.42 W, R = 0.84 Ω, and Z = 0.002377 1/K. © 2024 The Authors
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    Influence of Different Layers on Enhancing the PV Performance of Al/ZnO/ZnMnO/CIGSSe/Cu2O/Ni Solar Cells
    (Pleiades Publishing, 2024) Sawrab Sikder; Hosen R.; Uddin M.S.; Haque M.M.; Mamur H.; Bhuiyan M.R.A.
    Abstract: Copper Indium Gallium Sulfide Selenide (CIGSSe)-based solar cells, featuring Al/ZnO/ZnMnO/CIGSSe/Cu2O/Ni layers, are optimized using the solar cell capacitance simulator (SCAPS) for enhanced photovoltaic (PV) performance. The solar cell design incorporates a CIGSSe absorber layer, a zinc manganese oxide (ZnMnO) buffer layer, and a zinc oxide (ZnO) window layer. The upper/top and back contacts are made of aluminum (Al) and nickel (Ni), respectively, with an electron-reflected-hole transport layer (ER-HTL) of cuprous oxide (Cu2O). The performance of the proposed structure can be improved by adjusting the thicknesses of the absorber, buffer, and window layers, along with the acceptor and donor concentrations of the absorber and buffer layers, series and shunt resistance, and temperature. The configuration improves the cell structure’s open-circuit voltage (VOC), short-circuit current (JSC), fill factor (FF), and power conversion efficiency (PCE). For optimal outcomes, set the acceptor and donor concentrations in the absorber and buffer layers to 1017 and 1018 cm–3, respectively. Furthermore, keep the thicknesses of the absorber layer at 2000 nm, the window and buffer layers at 50 nm, and the ER-HTL at 10 nm. The optimized model demonstrates PV performance characteristics of 1.0642 V for VOC, 36.10 mA/cm2 for JSC, 81.06% for FF, and 31.15% for PCE under the AM1.5G spectrum. Furthermore, it exhibits a quantum efficiency of around 95.23% at visible wavelengths. © Allerton Press, Inc. 2024. ISSN 0003-701X, Applied Solar Energy, 2024, Vol. 60, No. 2, pp. 201–214. Allerton Press, Inc., 2024.