<p>Perovskite-based solar cells have gained popularity due to their distinct electrical and optical features. Cesium titanium bromide (Cs₂TiBr₆) has a bandgap of 1.8&#xa0;eV, making it a suitable lead-free perovskite absorber material for solar devices. In this work, we performed a numerical simulation of a solar cell configuration consisting of fluorine-doped tin oxide (FTO)/electron transport layer/buffer layer (CdS/SnS₂/Zn₂SnO₄)/Cs₂TiBr₆/hole transport layer/Ni. We wanted to replace the CdS buffer layer with a material that is nontoxic and readily accessible. Following a comprehensive investigation, it was determined that SnS₂ is a better option than CdS, which was previously thought to be the most appropriate material. We conducted a thorough investigation, comparing the photovoltaic properties of different buffer layers and active layer thickness and investigating their influence on the photovoltaic performance of solar cells. Simulated devices demonstrated the highest efficiencies for CdS-, SnS₂-, and Zn₂SnO₄-based simulated solar cells as 30.86%, 33.55%, and 27.50%, respectively. After thorough investigation, it was discovered that SnS₂ outperformed CdS and Zn₂SnO₄ as a buffer layer material. Thus, SnS₂ as a buffer layer resulted in power conversion efficiency of 33.55%. The short-circuit current density was 38.62 mAcm⁻², the open-circuit voltage was 0.9895&#xa0;V, and the fill factor was 87.8%. Based on our findings, Ni was recognized as the most effective back metal contact. This study has the potential to lay the foundation for the creation of thin-film solar cells utilizing Cs₂TiBr₆ as an absorber that are cost-effective, environmentally sustainable, and highly efficient.</p>