Solution-Processed Pure Blue Thermally Activated Delayed Fluorescence Emitter Organic Light-Emitting Diodes With Narrowband Emission

Abstract

There is a need to satisfy the high color purity requirement of display technology with a simply fabricated process. Herein, solution-processed blue thermally activated delayed fluorescence organic light-emitting diodes (OLEDs) with a narrow spectrum with a full width at half maximum (FWHM) of 32 nm and y color coordinate below 0.2 are demonstrated by employing a molecule containing boron and nitrogen atoms (TBN-TPA) as the guest emitter in the emissive layer. The opposite resonance positions of B-N atoms of TBN-TPA endows a multi-resonance effect, leading to high color purity.

A gold(iii)–TADF emitter as a sensitizer for high-color-purity and efficient deep-blue solution-processed OLEDs

“…7. 5,9,11,12,14,15 The preliminary lifetime of the device with 10 wt% Au-1 and 0.5 wt% n-DABNA was measured under our laboratory conditions. As shown in Fig.…”

“…[1][2][3][4] However, compared to green and red ones, the development of blue-emitting materials simultaneously possessing high efficiency and color purity is lagging behind, particularly for low-cost solution-processed OLEDs (SP-OLEDs) that require emissive dopants to be highly soluble in common solvents. [5][6][7][8][9][10][11][12][13][14][15][16] Wang, Shao, and co-workers recently developed through-space charge transfer polymers containing face-to-face aligned donors and acceptors for achieving efficient blue thermally activated delayed fluorescence (TADF) emission. 6 The SP-OLEDs made with these polymers exhibited high maximum external quantum efficiency (EQE max ) of 18.8%.…”

“…26 A high EQE max of 21.8% and EQE 1000 of 17.4% were achieved with the as fabricated pure green SP-OLEDs that showed CIE coordinates of (0.12, 0.63) and a narrow electroluminescent (EL) spectrum with a FWHM of 33 nm. Nonetheless, the examples of blue SP-OLEDs fabricated with multi-resonance TADF emitters are scarce, 15,27 and one of the related studies reported that the performance of SP-OLEDs was far inferior to that of vacuum-deposited OLEDs based on the same dopant probably attributable to the unsatisfactory film quality by the spin-coating method. 15 Multi-resonance TADF compounds usually show poor solubility as a result of their high molecular rigidity and planarity.…”

Understanding the Structure and Energy Transfer Process of Undoped Ultrathin Emitting Nanolayers Within Interface Exciplexes

“…Organic light-emitting diodes (OLEDs) are considered and applied as a feasible technology in high-quality display, solid-state lighting sources (SSLs), and near-infrared (NIR) applications, owing to the excellent advantages including high efficiency, low power consumption, and flexibility. ( Baek et al, 2020 ; Helander et al, 2011 ; Wang et al, 2011 ; Wang et al, 2020 ; Xu et al, 2017 ; Greiner et al, 2012 ; Zheng et al, 2013 ; Xu et al, 2021a ). Nevertheless, previous studies usually adopted complicated fabricated processes and device structures of OLEDs, which impede the popularizing of this promising technology.…”

Circular economy of ITO thin films deposited on glass obtained from degraded OLED devices

“…Organic light-emitting diodes (OLEDs) can be characterized as electroluminescent semiconductor devices that uses multilayer structures of organic materials 1,2 . The organic multilayer is inserted between an anode used as a transparent conductive oxide (TCO) and a cathode used as a metallic thin film 3,4 . OLED devices were presented in 1987 by two researchers of Eastman Kodak Company known as Ching Wang Tang and Steven Van Slyke 5 .…”