This study explores the performance of BaZrS₃ and Ba(Zr,Ti)S₃ chalcogenide perovskite solar cells (PSCs) through numerical simulations using SCAPS-1D. The research investigates the impact of various device configurations, including 12 electron transport layers (ETLs) and 13 hole transport layers (HTLs), on the power conversion efficiency (PCE) of these materials. By optimizing the thickness, carrier concentration, and defect density of the absorber, ETLs, and HTLs, the study identifies the optimal device structure for maximizing PCE. The best PCE of 28.08% is achieved for the device FTO/ZrS₂/BaZrS₃/SnS/Au, which benefits from a suppressed barrier height at the ZrS₂/BaZrS₃ interface and the degenerate behavior of SnS, enhancing charge carrier transportation and conductivity. Further optimization of the work function leads to an ohmic contact with Pt, increasing the PCE to 28.17%. The study also examines the effect of Ti alloying in BaZrS₃, finding that a 0.04 atom % Ti alloyed BaZrS₃ (Ba(Zr₀.₉₆Ti₀.₀₄)S₃) achieves a maximum PCE of 32.58% at a thickness of 700 nm due to extended absorption in the near-infrared (NIR) region. This improvement is attributed to the lower band gap of the alloyed material, which allows for more efficient light absorption and reduced recombination at the interfaces. The lattice mismatch between the transport layers and the absorber is also analyzed, showing that a reduction in mismatch through Ti alloying leads to fewer defects and enhanced performance. The study highlights the importance of band alignment between the absorber, ETL, and HTL in achieving high PCE. Proper band alignment ensures effective charge carrier separation and transport, reducing recombination losses and improving device efficiency. The research provides valuable insights into the design and optimization of BaZrS₃ and Ba(Zr,Ti)S₃ PSCs, offering a pathway for experimental realization of high PCE in these materials.This study explores the performance of BaZrS₃ and Ba(Zr,Ti)S₃ chalcogenide perovskite solar cells (PSCs) through numerical simulations using SCAPS-1D. The research investigates the impact of various device configurations, including 12 electron transport layers (ETLs) and 13 hole transport layers (HTLs), on the power conversion efficiency (PCE) of these materials. By optimizing the thickness, carrier concentration, and defect density of the absorber, ETLs, and HTLs, the study identifies the optimal device structure for maximizing PCE. The best PCE of 28.08% is achieved for the device FTO/ZrS₂/BaZrS₃/SnS/Au, which benefits from a suppressed barrier height at the ZrS₂/BaZrS₃ interface and the degenerate behavior of SnS, enhancing charge carrier transportation and conductivity. Further optimization of the work function leads to an ohmic contact with Pt, increasing the PCE to 28.17%. The study also examines the effect of Ti alloying in BaZrS₃, finding that a 0.04 atom % Ti alloyed BaZrS₃ (Ba(Zr₀.₉₆Ti₀.₀₄)S₃) achieves a maximum PCE of 32.58% at a thickness of 700 nm due to extended absorption in the near-infrared (NIR) region. This improvement is attributed to the lower band gap of the alloyed material, which allows for more efficient light absorption and reduced recombination at the interfaces. The lattice mismatch between the transport layers and the absorber is also analyzed, showing that a reduction in mismatch through Ti alloying leads to fewer defects and enhanced performance. The study highlights the importance of band alignment between the absorber, ETL, and HTL in achieving high PCE. Proper band alignment ensures effective charge carrier separation and transport, reducing recombination losses and improving device efficiency. The research provides valuable insights into the design and optimization of BaZrS₃ and Ba(Zr,Ti)S₃ PSCs, offering a pathway for experimental realization of high PCE in these materials.