Study the optoelectronic properties of PbI2 nanorods/Si photodetector prepared by magnetic field-assisted laser deposition route

Abstract

Here, we report the synthesis of lead iodide (PbI2) nanorods (NRs) by using magnetic field-assisted pulsed laser deposition (PLD). The structural, morphological, and optical properties of the films were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), photoluminescence (PL), Raman spectroscopy, and UV–Vis absorption. XRD results revealed that the deposited film was (001)-oriented polycrystalline with hexagonal structure (2H-polytype). The film crystallinity has been improved when it deposited under the effect of an external magnetic field. SEM showed that the film morphology changed completely from spherical nanosized to 450 nm long grain nanorods with 60 nm average diameter. The films’ optical energy gap before and after the application of magnetic field were 2.4 and 3.3 eV, respectively. The film exhibited red-shifted intense PL emission centered at 2.5 eV at a magnetic field of 0.4 T. The figures of merit of the photodetector were measured with and without the magnetic field. The responsivity of the PbI2/n-Si photodetector at λ = 560 nm increased from 0.22 A/W to 0.58 A/W at 7.5 V bias when magnetic field was applied during the deposition. The rise time of the photodetector prepared with magnetic field and without magnetic field was measured at 3 V bias.