Laser-Induced Optoelectronic and Crystallographic Tuning of Methyl Ammonium Iodobismuthate Perovskite for Improved Performance of Sandwich-Type Photodetectors

For the development of high-performance perovskite-based photodetectors, it is required that the optical and crystallographic properties of perovskite materials are enhanced through their modification. Many attempts on the modification of perovskite materials through introduction of dopants have resulted in an alteration of their chemical structure. Herein, we present a clean and structure-preserving technique for tuning the optical and crystallographic properties of bismuth-based lead-free perovskite materials through irradiation with 2.5 mJ laser pulses ejected from a Nd:YAG laser operating in its second harmonics. X-ray diffraction (XRD) spectra show improved crystallinity and reduced crystallite size, scanning electron microscopy (SEM) images show a defect-minimized surface morphology, photoluminescence (PL) spectra show a minimized rate of Auger recombination, and absorbance spectra show improved absorbance at a constant band gap value. Consequently, simplified sandwiched-architecture-type photodetectors fabricated with the modified bismuth-based perovskite materials display a maximum photodetectivity of 4.5 × 109 Jones, maximum photoresponsivity of 25 μA/W, maximum photosensitivity of about 104, and minimum optical switching time of 10 ms under testing conditions of -2 V bias voltage, 15 mW/cm2 incident solar light, and room temperature. Thus, laser pulse irradiation represents an alternative method for enhancing the optical and crystallographic properties of perovskite materials from which highly efficient classes of photonic and photovoltaic devices can be developed.