Numerical study of buffer layers to obtain high performance solar cell

With the help of the SCAPS simulation program, this study investigates the possible buffer layer in copper zinc tin sulfide (CZTS)/zinc oxide (ZnO) thin-film solar cells. The tin sulfide (SnS[Formula: see text] and cadmium sulfide (CdS) are taken into consideration. Based on electronic band structure analysis, SnS 2 exhibits a more favorable alignment of the conduction band than CZTS, which minimizes the barrier to energy transfer. SnS 2 buffer layer showed enhanced carrier generation because of its higher absorption coefficient. Quantum efficiency plots highlighted SnS 2 ’s superior performance in the 400–800[Formula: see text]nm range, where CZTS strongly absorbs. The [Formula: see text] buffer layer solar cell exhibited a larger J–V curve area, driven by a higher short-circuit current density ([Formula: see text].) of 24.27[Formula: see text]mA/cm 2 compared to 23.69[Formula: see text]mA/cm 2 for CdS, achieving an impressive 15.71% efficiency versus 15.35% for CdS. Because of improved band alignment, enhanced charge generation and higher quantum efficiency, [Formula: see text] is proving to be a promising buffer layer for high-efficiency CZTS solar cells.