Ferroelectric BiMnO3 in BSF layer and Zinc doped CdS in buffer layer: Boosting up the performance of CZTS solar cell

Abstract

In this work, numerical modelling and simulation of CZTS solar cell has been performed using SCAPS-1D. The alternative of toxic CdS buffer layer with <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{Zn}_{\mathrm{x}}\text{Cd}_{1-\mathrm{x}}\mathrm{S}(\mathrm{x}=0.1,0.2,0.3,0.6,0.8)$</tex> buffer layer in CZTS solar cell. Here, the effect of zinc concentration in overall performance (open circuit voltage, short circuit current, fill factor, efficiency) of CZTS solar cell is experimented. In this work, the main attempt is to take the advantages of multiferroic properties of ferroelectric material BiMnO3 (BMO) in the back surface field (BSF) layer. The maximum performance is evaluated by varying the thickness and doping concentration of buffer layer, absorber layer and back surface field layer for the structure of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{SnO}_{2}/\text{Zn}_{2}\text{SnO}_{4}/\text{Zn}_{\mathrm{x}}\text{Cd}_{1-} {}_{\mathrm{x}}\mathrm{S}/\text{CZTS}/\text{BiMnO}_{3}/\text{Cu}$</tex> with and without BSF layer. With ferroelectric material in BSF layer, the J-V curves are investigated for cell structure and the optimal photovoltaic parameters have been achieved with efficiency of 24.18%, fill <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{factor}=87.15\%, \mathrm{J}_{\text{sc}}=27.19$</tex> mA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{V}_{\text{oc}}=1.02\mathrm{V}$</tex> . As compared to the high performance CZTS solar cell model presented in the reference model which had efficiency of 23.72% with CdS in buffer layer and Pt in BSF layer, the proposed solar cell model in this work with zinc doped CdS in buffer layer and ferroelectric BMO in BSF layer enhanced the solar cell efficiency upto 24.18%. Here, the optical properties layer by layer photon density is also observed for CZTS solar cell with zinc doped CdS in buffer layer and BMO in back surface field (BSF) layer.