Sr²⁺doped CsPbBrI₂perovskite nanocrystals coated with ZrO₂for applications as white LEDs

Perovskite nanocrystals (NCs) feature adjustable bandgap, wide absorption range, and great color purity for robust perovskite optoelectronic applications. Nevertheless, the absence of lasting stability under continues energization, is still a major hurdle to the widespread use of NCs in commercial applications. In particular, the reactivity of red-emitting perovskites to environmental surroundings is more sensitive than that of their green counterparts. Here, we present a simple synthesis of ultrathin ZrO₂coated, Sr²⁺doped CsPbBrI₂NCs. Introducing divalent Sr²⁺may significantly eliminate Pb° surface traps, whereas ZrO₂encapsulation greatly improves environmental stability. The photoluminescence quantum yield of the Sr²⁺-doped CsPbBrI₂/ZrO₂NCs was increased from 50.2% to 87.2% as a direct consequence of the efficient elimination of Pb° surface defects. Moreover, the thickness of the ZrO₂thin coating gives remarkable heat resistance and improved water stability. Combining CsPbSr_0.3BrI₂/ZrO₂NCs in a white light emitting diode (LED) with an excellent optical efficiency (100.08 lm W^-1), high and a broad gamut 141% (NTSC) standard. This work offers a potential method to suppress Pb° traps by doping with Sr²⁺and improves the performance of perovskite NCs by ultrathin coating structured ZrO₂, consequently enabling their applicability in commercial optical displays.