Path Toward High-Efficiency CZTS Solar Cells with Buffer Layer Optimization

W. Hennia, W.L. Rahalb, c, D. Rachedd aElaboration and Characterization Physico-Mechanical and Metallurgical of Materials Laboratory, University Abdelhamid Ibn Badis of Mostaganem, Route National N °11, Kharouba, 27000, Mostaganem, Algeria bLaboratory of Analysis and Application of Radiation, Faculty of Physics, University of Sciences and Technology of Oran Mohamed Boudiaf, BP 1505, el Mnaouar, Oran, Algeria cPhysics Department, University Abdelhamid Ibn Badis of Mostaganem, Chemin des Crêtes, 27000, Mostaganem, Algeria dLaboratory of Plasma Physics, Conductive Materials and their Applications, University of Science and Technology of Oran Mohamed Boudiaf, BP 1505, el Mnaouar, Oran, Algeria

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In this work, we numerically improve the performance of kesterite thin film solar cells (ZnO/Cu2ZnSnS4/CdS/MoS2) using the Solar Cell Capacitance Simulator. The work carried out is mainly based on the study of the influence of the doping density, the thickness, and the gap energy of the buffer layer on the cell's performance. Based on the simulation results, it is found that increasing the buffer layer thickness strongly deteriorates the cell's performance. An optimized and economical CdS buffer layer with a thickness of 15 nm and band gap of 3.2 eV is proposed. It is also shown that it is important to control the doping density of this layer in order to obtain a compromise between the p-n junction electric field and the global recombination rate, to produce efficient solar cells. After optimizing the studied solar cell, promising results are achieved with a conversion efficiency of 17.93%, a fill factor of 71.23%, a short-circuit current density of 30.92 mA/cm2, and an open circuit voltage of 0.814 V. The obtained results will provide some important guidelines for producing high-efficiency Cu2ZnSnS4 solar cells.

DOI:10.12693/APhysPolA.142.445 topics: solar cell, CZTS, CdS, optimization