Zn2+-Doping-Assisted Preparation for Efficient Pure Red CsPbI ₃ Nanocrystals with Narrow Emission

CsPbI 3 perovskite nanocrystals (NCs) have emerged as promising materials for optoelectronic devices because of their superior optical properties. However, the brightness of the deep red fluorescence does not satisfy the requirements of outdoor displays. Herein, we report an effective strategy of Zn[Formula: see text]-assisted passivation to obtain pure red fluorescence and narrow emission CsPbI 3 NCs at a modified hot-injection method. It is found that the introduced Zn[Formula: see text] ions are successfully doped into the NCs lattice to replace some Pb[Formula: see text] ions for passivating some defects, increasing the radiative recombination rate and decreasing the nonradiative recombination rate. As a result, the as-prepared Zn[Formula: see text]-treated CsPbI3 (Zn-CsPbI[Formula: see text] has a luminescence peak position at 635[Formula: see text]nm and a narrow full width at half maximum of only 29.8[Formula: see text]nm, with photoluminescence quantum yield (PLQY) up to 81%, which is 30% higher than the pristine NCs. Meanwhile, the structure of the Zn-CsPbI 3 NCs is orthorhombic [Formula: see text] phases, and their morphology is a uniformly distributed hexagonal crystal system.