Boosting Stability of Hybrid Manganese Bromide Microcrystals by Zn2+ Substitution for Wide-Gamut Displays

Hybrid manganese bromides have emerged as promising lead-free narrow-band green emitters for wide-gamut displays, but their practical application is still limited by insufficient operational stability. Herein, Zn2+ substitution is employed to enhance the stability of tetraethylammonium manganese bromide (TEA2MnBr4) microcrystals (MCs) synthesized via an ultrafast self-assembly method. With increasing Zn2+ contents, the photoluminescence intensity of TEA2Mn1−xZnxBr4 MCs gradually decreases, while the x = 0.10 MCs still exhibit efficient narrow-band green emission at 518 nm and a high photoluminescence efficiency of about 85% under blue excitation. More importantly, Zn2+ incorporation substantially enhances the storage and thermal stability, as well as operational stability of the corresponding green LED devices (retaining above 99% of initial luminous efficacy after 160 h continuous operation at 20 mA). Finally, a white LED fabricated using the x = 0.10 MCs achieves a high luminous efficiency of about 136 lm/W and covers about 112% of the National Television System Committee 1931 color gamut. These results demonstrate that Zn2+ substitution is an effective strategy for stabilizing hybrid manganese bromide emitters and highlight their potential for lead-free wide-gamut display applications.