Perovskite photodetectors that incorporate organic–inorganic charge transport layers exhibit impressive sensing capabilities and enhanced stability against degradation, paving the way for numerous future applications. The tunability of perovskite materials enables the optimization of their optoelectronic properties, further boosting their performance. In this work, design and analysis of a lead-free perovskite photodetector has been conducted, using the SCAPS 1D simulator. SCAPS is a computer-based tool well-suited for analyzing HOMO and heterojunctions, as well as multi-junction and Schottky barrier optoelectronic devices. In this proposed design, the toxic lead-based perovskites, which are environmentally unsuitable, have been replaced with Cs3Sb2Br9, a lead-free perovskite material used as the absorber layer. Adding this absorber layer, the planar structure of FTO/PCBM/Absorber/MoO3 is numerically simulated and plotted in terms of current density, quantum efficiency and responsivity. The device demonstrates a gradual increase in QE and R when illuminated with wavelengths ranging from 350 to 600 nm. At 300ºK, responsivity of 0.362 A/W and QE of 75.8% has been observed. This work proposes a low cost, non-toxic, and stable PPD with wide range of detection due to high available bandwidth of Cesium antimony bromide material.