Large cation ethylammonium incorporated perovskite for efficient and spectra stable blue light-emitting diodes

• Published in: Nature communications Vol. 11; no. 1; pp. 4165 - 8
• Main Authors: Chu, Zema, Zhao, Yang, Ma, Fei, Zhang, Cai-Xin, Deng, Huixiong, Gao, Feng, Ye, Qiufeng, Meng, Junhua, Yin, Zhigang, Zhang, Xingwang, You, Jingbi
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 20.08.2020; Nature Publishing Group; Nature Portfolio
• Subjects: 140/131; 140/146; 639/301/1005/1007; 639/301/1019/1020/1091; Cations; Efficiency; Electroluminescence; Emission spectra; Emissions; Humanities and Social Sciences; Light emitting diodes; Luminescence; multidisciplinary; NMR; Nuclear magnetic resonance; Perovskites; Photoluminescence; Photons; Quantum efficiency; Science; Science (multidisciplinary); Spectral emittance; Thermal stress; X-ray diffraction
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-17943-6

Perovskite light-emitting diodes (PeLEDs) have showed significant progress in recent years; the external quantum efficiency (EQE) of electroluminescence in green and red regions has exceeded 20%, but the efficiency in blue lags far behind. Here, a large cation CH 3 CH 2 NH 2 + is added in PEA 2 (CsPbBr 3 ) 2 PbBr 4 perovskite to decrease the Pb–Br orbit coupling and increase the bandgap for blue emission. X-ray diffraction and nuclear magnetic resonance results confirmed that the EA has successfully replaced Cs + cations to form PEA 2 (Cs 1- x EA x PbBr 3 ) 2 PbBr 4 . This method modulates the photoluminescence from the green region (508 nm) into blue (466 nm), and over 70% photoluminescence quantum yield in blue is obtained. In addition, the emission spectra is stable under light and thermal stress. With configuration of PeLEDs with 60% EABr, as high as 12.1% EQE of sky-blue electroluminescence located at 488 nm has been demonstrated, which will pave the way for the full color display for the PeLEDs. Blue light-emitting diodes (LEDs) are critical for displays. Employing a large organic cation into a quasi-two dimensional perovskite with green emission, Chu et al. achieve LEDs exhibiting a high external quantum efficiency of 12.1% and stable spectra in the sky-blue region.