An optoelectronic device to detects incident light and convert it into an electrical signal is known as a photodetector. To obtain higher responsivity and detectivity of photo detector, suitable materials are required. In the present study, an inorganic leadfree perovskite CsSn 0.5 Ge0.5 I3 material is utilized as an active layer for photodetector applications, together with Nb2 O5 as electron transport layer (ETL) and CuSbSe2 as hole transport layer (HTL). The perovskite photodetector (PePd) is simulated by employing Solar Cell Capacitance Simulator-One Dimensional (SCAPS-1D) software. We have thoroughly investigated the impact of various parameters such as the defect density and donor concentration of active layer, series and shunt resistance, the thickness of active layer and metal work function of back contact using numerical simulation. Under standard AM 1.5G irradiance, we obtained the detectivity (D*) and responsivity (R) of the proposed photodetector are 3.3 × 10 13 Jones and 0.54 AW -1 respectively. The proposed device performances reveal that it is suitable for high performance photodetector.