Next Energy (Jan 2025)

Cu2FeSnS4-based heterojunction solar cells with MxOy (M=Cu, Ni)-back surface field layers: Impact of defect density states and recombination

  • Md Shafayet-Ul-Islam,
  • Abdul Kuddus,
  • Md Kabiruzzaman,
  • Syed Farid Uddin Farhad,
  • Abu Kowsar

Journal volume & issue
Vol. 6
p. 100196

Abstract

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Copper-based chalcogenide quaternary semiconductors have emerged as promising candidates for next-generation photovoltaic (PV) devices, owing to their unique electronic and photonic properties coupled with environmentally friendly compositions. This study explores the potential of copper-based absorber materials, specifically Cu2FeSnS4 (CFTS), as an absorber in heterojunction solar cells with Cu-/Ni-metal oxides back surface field (BSF) and SnS2 buffer layers using the SCAPS-1D Simulator. Initially, we assess the performance of CFTS-absorber solar cells and compare the key photovoltaic metrics with those of other Cu-based semiconductors including CuInxGa(1-x)Se2 (CIGS), Cu2ZnSnS4 (CZTS), Cu2CoSnS4 (CCTS), Cu2NiSnS4 (CNTS), Cu2BaSnS4 (CBTS), Cu2MnSnS4 (CMTS), to identify the most promising absorber. Subsequently, we optimize the layer properties, including active layer thickness, free-carrier concentration, bulk and interface defect density, and carrier recombination in potential CFTS. Further, we examine the impact of defects, and carrier recombination, including radiative, Shockley-Read-Hall (SRH), and Auger recombination. These detailed studies yield improved and competitive photoconversion efficiency, (PCE) of 27.31% (compared to 24.68%, without BSF) with open circuit voltage, (VOC) of 1.36 V, short-circuit current density, (JSC) of 22.28 mA/cm² and fill factor, (FF) of 90.47% for Cu2O, whereas the PCE of 26.97% with VOC of 1.07 V, JSC of 28.82 mA/cm² and FF of 86.91% for NiOx BSF layer in Au/Mo/BSF(Cu2O and NiOx)/CFTS/SnS2/ZnMgO/ZnO:Al/Pt configurations under optimized conditions. The enhanced charge separation and carrier collection efficiencies reveal the strong potential of CFTS absorber heterostructures with Cu2O/NiOx, SnS2, and bi-layer ZnMgO/ZnO:Al as BSF, buffer, and window layers, repectively, providing insights and resources for developing high-efficiency CFTS-based photovoltaic devices.

Keywords