A numerical investigation to design and performance optimization of lead-free Cs₂TiCl₆ based perovskite solar cells...

Among the most attractive light-absorbing materials, halide perovskites have been gaining popularity for their versatile range of use in solar cells, lasers, and photodetectors. Whereas, Titanium (Ti)-based all-inorganic perovskite solar cells (PSCs) have garnered attention for their optoelectronic capabilities in response to this situation. In this theoretical study, Cesium Titanium (IV) Halide based lead-free, eco-friendly, and stable Cs₂TiCl₆-based PSC has been proposed and a numerical simulation using SCAPS-1D has been carried out to enhance the cell performance by optimizing the device parameters. A different set of hole transport layers (HTLs) like MoO_3, ZnTe, CNTS, CuAlO_2, CdTe, nPB, C₆TBTAPH_2, N: TiO_2, NiCo₂O_4, and PBTTT-C14 was simulated in combination with electron transport layers(ETLs) such as CdS, Nb₂O₅, ZnSe, and MZO. After several cell optimizations like thickness, acceptor, donor, and defect concentration of selected four structures, the best cell structure are suggested e.g., FTO/CdS/Cs₂TiCl₆/CdTe/Au that shows a PCE of 18.15% along with the short circuit current density (J_SC) of 17.83 mA/cm², open-circuit voltage (V_OC) of 1.188 V, fill factor (FF) of 89.51%. Among all devices, the solar cell performance decreases when series resistance (R_S) and temperature are increased as opposed to shunt resistance (R_Sh). The obtained results reveal that Cs₂TiCl₆-based PSC can contribute to the advancement of efficient non-toxic, all-organic perovskite solar cells in the future.