Enhanced Optical Properties and Stability of CsPbBr₃ Nanocrystals Through Nickel Doping

Abstract

Abstract To improve the quantum efficiency and stability of perovskite quantum dots, the structural and optical properties are optimized by varying the concentration of Ni doping in CsPbBr 3 perovskite nanocrystals (PNCs). As Ni doping is gradually added, a blue shift is observed at the photoluminescence (PL) spectra. Ni‐doped PNCs exhibit stronger light emission, higher quantum efficiency, and longer lifetimes than undoped PNCs. The doped divalent element acts as a defect in the perovskite structure, reducing the recombination rate of electrons and holes. A stability test is used to assess the susceptibility of the perovskite to light and moisture. For ultra‐violet light irradiation, the PL intensity of undoped PNCs decreases by 70%, whereas that of Ni‐doped PNCs decreases by 18%. In the water addition experiment, the PL intensity of Ni‐doped PNCs is three times that of undoped PNCs. For CsPbBr 3 and Ni:CsPbBr 3 PNCs, a light emitting diode is fabricated by spin‐coating. The efficiency of Ni:CsPbBr 3 exceeds that of CsPbBr 3 PNCs, and the results significantly differ based on the ratio. A maximum luminance of 833 cd m –2 is obtained at optimum efficiency (0.3 cd A –1 ). Therefore, Ni‐doped PNCs are expected to contribute to future performance improvements in display devices.