Conjugated amidine ligands enhance the performance of perovskite nanocrystal blue light-emitting diodes prepared in air with green solvents. Issue 43 (29th October 2021)

• Record Type: Journal Article
• Authors: Li, Teng; Zhang, Huijun; Yu, Cong; Wang, Pang; Wang, Hui; Zhang, Xiaoshuai; Sun, Yuandong; Liu, Dan; Wang, Tao
• Is Part Of: Journal of materials chemistry. Volume 9:Issue 43(2021)
• Page Start: 15488
• Page End: 15495
• Publication Date: 2021-10-29
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d1tc03435a
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : π-Conjugated benzamidine hydrochloride is introduced into CsPbBrx Cl3−x NCs to reduce Cs + and halide vacancies and suppress nonradiative recombination, leading to spectrally stable blue PeLEDs with reduced turn-on voltage, enhanced EQE and luminance. Abstract : Metal halide perovskite nanocrystals (NCs) are attracting increasing attention due to their potential in fabricating high-performance perovskite light-emitting diodes (PeLEDs). Compared to those of green and red PeLEDs, the performance of blue PeLEDs lags far behind, which seriously hinders the application of perovskite NCs in full-color lighting and display applications. Among the various strategies to improve the performance of blue PeLEDs based on perovskite NCs, surface ligand engineering shows great potential. Herein, amidine ligands, including acetamidine hydrochloride (AMCl), pentanimidamide hydrochloride (PMCl) and benzamidine hydrochloride (BMCl), are introduced into room-temperature synthesized CsPbBr x Cl3− x NCs in air using green solvents, which are found to reduce both Cs + and halide vacancies on the NC surface and suppress nonradiative recombination. The π-conjugated amidine BMCl can also improve the charge transport of perovskite NCs, leading to spectrally stable blue PeLEDs with a dramatically reduced turn-on voltage from 4.4 to 3.0 V, and an enhanced EQE of 2.30% and a luminance of 205 cd m −2 at 479 nm.