Preparation of MAPbI3 perovskite film by pulsed laser deposition for high-performance silicon-based heterojunction photodetector

This study investigates the preparation and characterization of CH3NH3PbI3 (MAPbI3) perovskite thin films. The films were prepared using a one-step pulsed laser deposition technique at different laser fluences. Structural, optical, and electrical properties of CH3NH3PbI3 films were investigated at various laser fluences. The X-ray diffraction (XRD) studies confirm the formation of β-MAPbI3 films. The optical energy gap of MAPbI3 perovskite film was calculated and is found to be in the range of 1.53–1.68 eV. Scanning electron microscope (SEM) analysis reveals the formation of rod-like and platelet morphologies, while energy dispersive X-ray spectroscopy analysis reveals that the [I]/[Pb] ratio of the films prepared with 2, 2.5, and 3 J/cm2 was 1.3, 2.3, and 1.36, respectively. Hall effect results confirm that the MPPbI3 films are p-type and the mobility of MAPbI3 film decreases from 0.26 to 0.084 cm2V−1s−1 as laser fluence increases from 2 to 3 J/cm2. The optoelectronic characteristics of the p-MAPbI3/n-Si photodetector were investigated as a function of laser fluence. By selecting an optimum laser fluence, a maximum responsivity of 2.57 A/W and an external quantum efficiency of 7.08 × 102% at 450 nm were obtained. The energy band lineup of the p-MAPbI3/n-Si photodetector fabricated with 2.5 J/cm2 was constructed.