Zero-dimensional perovskite-based nanocrystals (NCs) of CsPbBr₃ embedded Cs₄PbBr₆ (CsPbBr₃@Cs₄PbBr₆) are becoming the most attractive material due to their excellent optical performance and better stability compared with high-dimensional perovskites. The as-synthesized CsPbBr₃@Cs₄PbBr₆ NCs can be used to fabricate quantum dot light-emitting diode (QLED) devices and mini LEDs.