As lead halide perovskites face toxicity and stability issues, research on the eco-friendly double perovskite Cs2AgBiBr6 has become increasingly popular. While the majority of research on this Cs2AgBiBr6 perovskite material has been concentrated on photovoltaic performance and promising applications, its enduring stability and degradation process have received far less attention. This article presents a thorough numerical analysis of an eco-friendly Cs2AgBiBr6 double perovskite solar cell (PSC) model with a standard n-i-p architecture FTO/C60/Cs2AgBiBr6/MoS2/Pt. In-depth research has been done on several device characteristics, including the defect density and the thickness of the electron transport layer (ETL), hole transport layer (HTL), and absorber layer, and back-contact electrode work function. Through parameter optimization, we were able to achieve an open-circuit voltage (V oc) of 0.84 V, short-circuit current density (J sc) of 32.28 mA/cm2, and fill factor (FF) of 85.77% with power conversion efficiency (PCE) of 23.49% under AM1.5G illumination, which is significantly greater than the highest stated values identified in the literature.