Sr2+ doped CsPbBrI2 perovskite nanocrystals coated with ZrO2 for applications as white LEDs

Abstract

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 ZrO2 coated, Sr2+ doped CsPbBrI2 NCs. Introducing divalent Sr2+ may significantly eliminate Pb° surface traps, whereas ZrO2 encapsulation greatly improves environmental stability. The photoluminescence quantum yield of the Sr2+-doped CsPbBrI2/ZrO2 NCs 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 ZrO2 thin coating gives remarkable heat resistance and improved water stability. Combining CsPbSr0.3BrI2/ZrO2 NCs 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 Sr 2+and improves the performance of perovskite NCs by ultrathin coating structured ZrO2, consequently enabling their applicability in commercial optical displays.