Single Bi<sup>3+</sup> Ultrabroadband White Luminescence in Double Perovskite via Crystal Lattice Engineering toward Light‐Emitting Diode Applications
Sheng Wu, Quan Liu, Puxian Xiong, Weiwei Chen, Quan Dong, Dongdan Chen, Dong Wang, Guoxing Zhang, Yan Chen, Guogang Li
Abstract
Abstract Single‐phase white luminescence phosphors are emerging for potential phosphor‐converted white light‐emitting diodes (pc‐WLEDs) and alternatives to trichromatic phosphor blends. In this work, Ba 2 ZnWO 6 :Bi 3+ phosphors are prepared by a high‐temperature solid‐state reaction method and the luminescent properties are investigated. The broadband excitation from 250 to 400 nm is perfectly matched with the emission of nearly ultraviolet (n‐UV) InGaN chip, which ultrabroadband emission band (full width at half maximum = 217 nm) can cover a wider luminescence region. Li + /Na + /K + codoping is more desirable for the ultrabroadband emission of Ba 2 ZnWO 6 :0.006Bi 3+ due to the charge compensation and rationally designed lattice distortion while improving the thermal stability of the phosphor. Furthermore, tunable emissions can be achieved either by changing the content of doped ions or the excitation wavelength due to the different occupation of Ba 2+ and Zn 2+ sites by Bi 3+ ions. Finally, single‐phase warm WLED (( x , y ) = (0.4170, 0.4035)) devices with a correlated color temperature of 3329 K and color rendering index of Ra = 75.3 are successfully prepared using Ba 2 ZnWO 6 :0.006Bi 3+ , 0.03Na + phosphor, and 365 nm InGaN chips. These results indicate that Ba 2 ZnWO 6 :Bi 3+ has excellent potential as phosphor for n‐UV pc‐WLEDs and provides new ideas for the application of ultrabroadband emitting phosphors in WLEDs.