Tuning of bandgap for warm white light emissions in indium-doped cesium metal halide perovskites by solvothermal method

Cesium-based perovskites, particularly Cs₃Bi₂Br₉, doped with indium, have emerged as promising materials for energy-efficient lighting, notably in white light-emitting diodes (WLEDs). This study aimed to address environmental concerns associated with lighting technology by employing solvothermal synthesis to fabricate these materials. Comprehensive characterization techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM), and photoluminescence spectroscopy (PL), were applied to assess their properties. XRD analysis confirmed the formation of Cs₃Bi₂Br₉ with a trigonal crystal structure and indium doping induced significant changes in the material’s color and crystal lattice. TEM imaging, even after six months, revealed the presence of stable nanocrystals, indicating the material’s durability in practical applications. UV–Vis absorption and photoluminescence spectroscopy showed variable bandgaps and efficient photon emission. Notably, as the indium doping concentration increased, the emitted light shifted from blue to bluish-white, making these materials highly suitable for the synthesis of WLEDs. This research offers a promising prospect to address environmental issues associated with lighting technology while advancing energy-efficient illumination solutions.