The defect density of the absorber layer plays a pivotal role in determining the output parameters of a perovskite solar cell (PSC). Defect density impacts carrier collection efficiency, diffusion length, carrier lifetime, and recombination rates, all of which collectively influence overall device performance. High defect density in the absorber layer introduces trap states, which act as recombination centers for charge carriers. This increases non-radiative recombination losses, ultimately reducing the short-circuit current density (Jsc), open-circuit voltage (Voc), fill factor (FF), and overall power conversion efficiency (PCE).