Spectra stable deep-blue light-emitting diodes based on cryolite-like cerium(III) halides with nanosecond d-f emission

Qingxun Guo; Liang Wang; Longbo Yang; Jiashun Duan; Hainan Du; Guoqi Ji; Nian Liu; Xue Zhao; Chao Chen; Ling Xu; Liang Gao; Jiajun Luo; Jiang Tang

doi:10.1126/sciadv.abq2148

Spectra stable deep-blue light-emitting diodes based on cryolite-like cerium(III) halides with nanosecond d-f emission

Sci Adv. 2022 Dec 16;8(50):eabq2148. doi: 10.1126/sciadv.abq2148. Epub 2022 Dec 16.

Authors

Qingxun Guo¹, Liang Wang¹, Longbo Yang¹, Jiashun Duan¹, Hainan Du¹, Guoqi Ji¹, Nian Liu¹, Xue Zhao¹, Chao Chen¹, Ling Xu¹, Liang Gao^{1

2}, Jiajun Luo^{1

2}, Jiang Tang^{1

2}

Affiliations

¹ Wuhan National Laboratory for Optoelectronics (WNLO) and School of Optical and Electronic Information, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan, Hubei 430074, P. R. China.
² Optics Valley Laboratory, 1037 Luoyu Road, Wuhan, P. R. China.

Abstract

Next-generation wide color gamut displays require the development of efficient and toxic-free light-emitting materials meeting the crucial Rec. 2020 standard. With the rapid progress of green and red perovskite light-emitting diodes (PeLEDs), blue PeLEDs remain a central challenge because of the undesirable color coordinates and poor spectra stability. Here, we report Cs₃CeBr_xI_6-x (x = 0 to 6) with the cryolite-like structure and stable and tunable color coordinates from (0.17, 0.02) to (0.15, 0.04). Further encouraged by the short exciton lifetime (26.1 ns) and high photoluminescence quantum yield (~76%), we construct Cs₃CeBr_xI_6-x-based rare-earth LEDs via thermal evaporation. A seed layer strategy is conducted to improve the device's performance. The optimal Cs₃CeI₆ device achieves a maximum external quantum efficiency of 3.5% and a luminance of 470 cd m^-2 with stable deep-blue color coordinates of (0.15, 0.04). Our work opens another avenue to achieving efficient and spectrally stable deep-blue LEDs.