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ARTICLE

Modeling and optimization of a CZT(S,Se)-based tandem solar cell

B. Yassine, B. Tahar^*, G. Fathi, B. Meriem, B. Ibtissem

LNCSM, Department of Physics, ENS Kouba, Alger, Algeria

* Corresponding Author:

Chalcogenide Letters 2025, 22(7), 637-648. https://doi.org/10.15251/CL.2025.227.637

Received 30 January 2025; Accepted 16 July 2025; Issue published 17 December 2025

Abstract

In this paper, we designed a two-junction (tandem) solar cell model (tandem solar cell), consisting of an top and bottom subcell with absorber layers of Cu₂SnZnS₄ (CZTS) and Cu₂SnZnSe₄ (CZTSe) materials, respectively, for each subcell with a ZnS buffer layer and a ZnO window layer. This model was validated using the SCAPS-1D numerical simulation program. We also optimized the performance of the tandem cell as a whole using the simulation by studying the effect of the thickness of the absorber layer of the top subcell and the thickness of the absorber layer of the bottom subcell and its doping. The results of the study gave the optimal thickness value X_CZTS=142,8nm for the top subcell absorber layer, the optimal thickness value X_CZTSe=1µm for the bootom subcell absorber layer and its optimal doping value N_A/CZTSe=10¹⁹ cm^-3 Tandem cell characteristics corresponding to these optimal values are open-circuit voltage V_oc=1,4861V, short circuit current J_sc=18,59mA/cm² , fill factor FF=73.12% and efficiency ɳ=20,20%.

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Keywords

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