CsPbBr3:Na with an Adjustable Bandgap, Improved Luminescence Stability, and its Application in WLEDs with Excellent Color Quality and Vision Performance

Abstract It is still a great challenge to obtain multicolor tunable luminescence and improve the stability of luminescence through reasonable design of materials in the field of white light‐emitting diodes (WLEDs). In particular, it is more important to improve the luminescence intensity and stability of blue‐emitting materials. Here, the properties of CsPbBr3, CsPbBr3:Na, and NaPbBr3 are investigated theoretically by using density functional theory (DFT). Based on the DFT theoretical calculation results, it is assumed that unexpected performance may be achieved by replacing Cs in CsPbBr3 with Na or passivating the surface of CsPbBr3 with Na. As expected, the tunable luminescence from blue to green is successfully achieved from CsPbBr3:Na, and the stability is improved. After experimental optimization, the obtained CsPbBr3:Na (CPBN‐4) with high luminescence stability is used as blue‐emitting materials to construct the WLED devices with excellent color quality (CRI 92) and correlated color temperature of 9582 K.