Double perovskites (DPs) are one of the most promising candidates for developing white light-emitting diodes (WLEDs) owing to their intrinsic broadband emission from self-trapped excitons (STEs). Translation of three-dimensional (3D) DPs to one-dimensional (1D) analogues, which could break the octahedral tolerance factor limit, is so far remaining unexplored. Herein, by employing a fluorinated organic cation, we report a series of highly luminescent 1D DP-inspired materials, (DFPD)2 MI InBr6 (DFPD=4,4-difluoropiperidinium, MI =K+ and Rb+ ). Highly efficient warm-white photoluminescence quantum yield of 92 % is achieved by doping 0.3 % Sb3+ in (DFPD)2 KInBr6 . Furthermore, single-component warm-WLEDs fabricated with (DFPD)2 KInBr6 :Sb yield a luminance of 300 cd/m2 , which is one of the best-performing lead-free metal-halides WLEDs reported so far. Our study expands the scope of In-based metal-halides from 3D to 1D, which exhibit superior optical performances and broad application prospects.
Keywords: Film; One-Dimensional Double Perovskite; Self-Trapped Emission; Warm White-Light-Emitting Diodes.
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