Author(s): Chu, ZM (Chu, Zema); Zhao, Y (Zhao, Yang); Ma, F (Ma, Fei); Zhang, CX (Zhang, Cai-Xin); Deng, HX (Deng, Huixiong); Gao, F (Gao, Feng); Ye, QF (Ye, Qiufeng); Meng, JH (Meng, Junhua); Yin, ZG (Yin, Zhigang); Zhang, XW (Zhang, Xingwang); You, JB (You, Jingbi)

Source: NATURE COMMUNICATIONS Volume: 11 Issue: 1 Article Number: 4165 DOI: 10.1038/s41467-020-17943-6 Published: AUG 20 2020

Abstract: 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 CH3CH2NH2+ is added in PEA(2)(CsPbBr3)(2)PbBr4 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)PbBr4. This method modulates the photoluminescence from the green region (508nm) into blue (466nm), 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 488nm 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.

Accession Number: WOS:000568893000004

PubMed ID: 32820166

ISSN: 2041-1723

Full Text: https://www.nature.com/articles/s41467-020-17943-6