Low-cost lead-free inorganic perovskite photodetector with Cl@SnO2 as electron transport material and carbon as back contact

In this work, an n-i-p perovskite photodetector (PePd) architecture comprising a lead-free cesium tin-germanium triiodide (CsSn0.5Ge0.5I3) as an absorber layer, molybdenum trioxide (MoO3) as hole transport material (ETM) and chlorine passivated tin oxide (Cl@SnO2) as electron transport material is numerically modelled and simulated using SCAPS-1D tool. Influence of several device parameters such as defects in absorber layer, operating temperature, doping concentration, effect of different back contacts, interface defect density etc., is studied as a function of cell parameters, i.e., the short circuit current density (Jsc), J-V behaviour and Quantum efficiency (QE) response to explore the PePd performance of the architecture of the device. It has been observed that by employing proposed PePd structure FTO/Cl@SnO2/CsSn0.5Ge0.5I3/MoO3/C, Jsc of 26.74904 mA/cm2, responsivity (R) of 0.44 A/W and detectivity (D*) of 7.9 × 1013 Jones. The results show that CsSn0.5Ge0.5I3 can play an important role as an absorbing perovskite in the development of optoelectronic devices. •SCAPS-1D simulation software is used for simulation study.•The study shows that device performance strongly depends on various parameters.•Impact of defect density at Cl@SnO2/CsSn0.5Ge0.5I3 interfaces has been studied.•Using Cl@SnO2 and MoO3 as ETM and HTM respectively, optimum Jsc is obtained as 26.74904 mA/cm2.•The optimum R and D* are 0.44 A/W and 7.9 × 1013 Jones respectively.