Chloride Insertion–Immobilization Enables Bright, Narrowband, and Stable Blue-Emitting Perovskite Diodes

• DOI: 10.1021/jacs.9b12323
• Publication Date: 2020-03-09T19:27:03Z
• Authors: Dongxin Ma; Petar Todorović; Shadi Meshkat; Makhsud I. Saidam...; Ya-Kun Wang; Bin Chen; Peicheng Li; Benjamin Scheffel; Rafael Quintero-B...; James Z. Fan; Yitong Dong; Bin Sun; Chao Xu; Chun Zhou; Yi Hou; Xiyan Li; Yuetong Kang; Oleksandr Voznyy; Zheng-Hong Lu; Dayan Ban; Edward H. Sargent
• Keywords: Blueshift; Narrowband

Metal halide perovskites show promise for light-emitting diodes (LEDs) owing to their facile manufacture and excellent optoelectronic performance, including high color purity spectral stability, especially in the green region. However, blue perovskite LEDs, emission spectrum line width is broadened over 25 nm by coexistence of multiple reduced-dimensional domains, stability poor, with an undesirable shift (over 7 nm) toward longer wavelengths under operating conditions, degradation that occurs due phase separation when mixed halides are employed. Here we demonstrate chloride insertion-immobilization, a strategy enables first exhibit narrowband (line 18 spectrally stable (no wavelength shift) performance. We prepare bromide-based then employ organic chlorides dynamic treatment, inserting situ immobilizing blue-shift stabilize emission. achieve sky-blue LEDs record luminance 5100 cd/m2 at 489 nm, half-life 51 min 1500 cd/m2. By device structure optimization, further realize improved EQE 5.2% 479 90 100