Design and Modelling of High-Efficient HTL Free Perovskite-Based Photodetector Using Impedance Spectroscopy

Present days, the design of HTL free photo detectors plays an important role in optoelectronic devices due to its high stability, simple structure and easy fabrication process. We have designed the HTL free photo detector with ZnO as an electron transport layer (ETL) fabricated using RF sputtering and the perovskite material CH3NH3PbI3 as a light absorbing material deposited using two-step spin coating method. The optical and structural properties of fabricated sample are investigated by using UV-Vis spectroscopy and FTIR. Also, the electronic properties like band structure and density of states (DoS) of the ZnO and Perovskite material primitive cells are calculated by using density functional theory DFT with Quantum Espresso (QE) software package. The obtained band gap of the perovskite layer (~1.51 eV) is exactly matched with the experimental results. The performance of the device is modelled by using SETFOS software with the impedance spectroscopy technique by changing different metal electrodes like, Ag, Au, Pd and Pt. Among all, the Pt electrode showed high current density (18.6914 mA/cm^2), high fill factor (0.558) and maximum power conversion efficiency (18.5%).