Highly Efficient Quasi‐2D Green Perovskite Light‐Emitting Diodes with Bifunctional Amino Acid. Issue 13 (21st April 2022)

• Record Type: Journal Article
• Authors: Liu, Chenwei; Liu, Yongjie; Wang, Shuxin; Liang, Jiwei; Wang, Cheng; Yao, Fang; Ke, Weijun; Lin, Qianqian; Wang, Ti; Tao, Chen; Fang, Guojia
• Is Part Of: Advanced optical materials. Volume 10:Issue 13(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-04-21
• Subjects: defect passivation -- energy funneling -- green light‐emitting diodes -- phase adjustment -- quasi‐2D perovskites; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.202200276
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: Quasi‐two‐dimensional (quasi‐2D) perovskite light‐emitting diodes (PeLEDs) are considered as one of the most potential candidates in electroluminescence territory owing to their unique quantum confinement effect and excellent thermal stability of the light. Nevertheless, heterogeneous energy domain distribution leads to severe non‐radiative recombination in the process of energy transfer, which enormously hinders the performance and application of PeLEDs. Herein, an ambipolar amino acid, 5‐aminovaleric acid (5AVA), is demonstrated to be able to coordinate lead and halides simultaneously with its carboxyl and amidogen groups. The coordinated ambipolar molecule not only reconstitutes energy domains of perovskites but also minimizes the interfacial defects of PeLEDs. Accordingly, the presence of 5AVA in perovskite precursors leads to dramatic suppression of the n = 1 and n = 2 phases and accelerates energy transfer from wide bandgap domains to narrow bandgap ones. As a result, maximum external quantum efficiency (EQE) of 19.3% (18.20% ± 1.10%) is achieved in quasi‐2D green PeLEDs with current efficiency of 61.7 cd A −1 . Abstract : An ambipolar amino acid, 5‐aminovaleric acid (5AVA), is demonstrated to be able to coordinate lead and halides simultaneously with its carboxyl and amidogen groups. Those interactions not only reconstitute energy domains but also minimize the interfacial defects of perovskite films. Therefore, a maximum external quantum efficiency of 19.3% is achieved in quasi‐2D green perovskite light‐emitting diodes with current efficiency of 61.7 cd A −1 .