Influence of a lecithin additive on the performance of all-inorganic perovskite light-emitting diodes

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Vol. 7; no. 10; pp. 2905 - 2910
• Main Authors: Sun, Shuang-Qiao, Hua, Xiao-Chen, Liu, Qing-Wei, Wang, Tong-Tong, Luo, Wei, Zhang, Yi-Jie, Liao, Liang-Sheng, Fung, Man-Keung
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 2019
• Subjects: Current efficiency; Fluorescence; Lecithin; Light emitting diodes; Optoelectronics; Organic light emitting diodes; Perovskites; Quantum efficiency; Spin coating; Surface roughness; Surface stability
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/C8TC06365F

All-inorganic halide perovskites with superior optoelectronic properties are promising materials for efficient perovskite light-emitting diodes. However, they usually suffer from a large grain size (hundreds of nanometers), high surface roughness and poor stability during the spin coating process. Here, we report a facile strategy to fabricate a uniform and flat CsPbBr 3 film. A small amount of lecithin (LE) introduced into CsPbBr 3 precursor solution can promote the formation of small CsPbBr 3 grains that remarkably improve the uniformity of perovskite films with a surface roughness of about 2.2 nm. Furthermore, the CsPbBr 3 –LE films display excellent fluorescence stability in ambient air and LED devices based on the CsPbBr 3 –5 wt% LE film exhibit a current efficiency (CE) of 24 cd A −1 with an external quantum efficiency (EQE) of 6.5%. Therefore, it is anticipated that the findings of the present study will have great potential to boost the development of PeLEDs.