High-brightness thermally evaporated perovskite light-emitting diodes via dual-interface engineering

• Published in: Optical materials Vol. 150; p. 115223
• Main Authors: Xu, Li, Zhou, Lingfeng, Yan, Minxing, Luo, Guangjie, Yang, Deren, Fang, Yanjun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2024
• Subjects: Charge injection; High-brightness; Light-emitting diode; Perovskite; Surface passivation; Thermal evaporation; Perovskite; High-brightness; Charge injection; Light-emitting diode; Surface passivation; Thermal evaporation
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2024.115223

Thermal evaporation emerges as a promising method for the scale-up fabrication of perovskite light-emitting diodes (PeLEDs) due to its superior repeatability and compatibility with the existing display industry compared to conventional solution process. However, the brightness of current high-efficiency thermally evaporated PeLEDs is generally constrained to a range of thousands of cd/m2. Herein, we propose a dual-interface engineering strategy to modulate the charge injection properties and passivate surface defects in the co-evaporated Cs–Pb–Br perovskite emitter. Our findings demonstrate that introducing 4,4′-Cyclohexylidenebis [N, N-bis(4-methylphenyl) benzenamine] additive to the bottom hole transport layer poly (9-vinylcarbazole) not only facilitates hole injection but also increases the conductivity. Meanwhile, the deposition of functionalized phenylethylammonium bromide salts with a specific number of fluorine atoms passivates the top surface defects and enhances the charge transport simultaneously. Consequently, the optimal PeLEDs achieve a maximum luminance of 75,012 cd/m2, marking one of the brightest thermally evaporated PeLEDs reported to date. The proposed strategy holds significant potential to guide the preparation of high-performance thermally evaporated PeLEDs for high-radiance display applications. [Display omitted] •PVK-TAPC composite hole transport layer was utilized to reduce the hole injection barrier and increase the conductivity.•Fluorine functionalized PEABr salts were employed to passivate surface defects and modulate charge injection properties of PeLEDs.•The devices exhibited high luminance of 75,012 cd/m2, marking one of the brightest thermally-evaporated PeLEDs ever reported.