Large‐Area Blade‐Coated Deep‐Blue Polymer Light‐Emitting Diodes with a Narrowband and Uniform Emission. Issue 6 (27th December 2022)

• Record Type: Journal Article
• Authors: Wang, Shengjie; Sun, Lili; Zheng, Yingying; Zhang, Yahui; Yu, Ningning; Yang, Jinghao; Li, Mengyuan; Chen, Wenyu; He, Liangliang; Liu, Bin; Ni, Mingjian; Liu, Heyuan; Xu, Man; Bai, Lubing; Lin, Jinyi; Huang, Wei
• Is Part Of: Advanced science. Volume 10:Issue 6(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-27
• Subjects: blade‐coating processing -- large‐area deep‐blue polymers light‐emitting diodes -- polydiarylfluorenes -- single‐chain emission behavior -- uniform deep‐blue emission; Science -- Periodicals; 505
• DOI: 10.1002/advs.202205411
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: Large‐area polymer light‐emitting diodes (PLEDs) manufactured by printing are required for flat‐panel lighting and displays. Nevertheless, it remains challenging to fabricate large‐area and stable deep‐blue PLEDs with narrowband emission due to the difficulties in precisely tuning film uniformity and obtaining single‐exciton emission. Herein, efficient and stable large‐area deep‐blue PLEDs with narrowband emission are prepared from encapsulated polydiarylfluorene. Encapsulated polydiarylfluorenes presented an efficient and stable deep‐blue emission (peak: 439 nm; full width at half maximum (FWHM): 39 nm) in the solid state due to their single‐chain emission behavior without inter‐backbone chain aggregation. Large‐area uniform blade‐coated films (16 cm 2 ) are also fabricated with excellent smoothness and morphology. Benefitting from efficient emission and excellent printed capacity, the blade‐coated PLEDs with a device area of 9 mm 2 realized uniform deep‐blue emission (FWHM: 38 nm; CIE: 0.153, 0.067), with a corresponding maximum external quantum efficiency and the brightness comparable to those of devices based on spin‐coated films. Finally, considering the essential role of deep‐blue LEDs, a preliminary patterned PLED array with a pixel size of 800 × 1000 µm 2 and a monochrome display is fabricated, highlighting potential full‐color display applications. Abstract : Large‐area blade‐coated deep‐blue polymer light‐emitting diodes (PLEDs) are fabricated based on encapsulated polydiarylfluorenes. Large‐area blade‐coated film presents a robust deep‐blue emission, associated with their intrachain singlet excitonic behavior. Large‐area deep‐blue PLEDs are obtained with a narrow‐band emission of FWHM ≈ 38 nm and a CIE of (0.153, 0.067), which are applied in the patterned pixel array and monochrome display.