Achieving High Efficiency and Pure Blue Color in Hyperfluorescence Organic Light Emitting Diodes using Organo‐Boron Based Emitters. (16th December 2021)

• Record Type: Journal Article
• Authors: Naveen, Kenkera Rayappa; Lee, Hyuna; Braveenth, Ramanaskanda; Karthik, Durai; Yang, Ki Joon; Hwang, Soon Jae; Kwon, Jang Hyuk
• Is Part Of: Advanced functional materials. Volume 32:Number 12(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-12-16
• Subjects: boron blue TADF -- DABNA -- FRET -- hyperfluorescence -- OLED; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202110356
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: In the field of organic light‐emitting diodes, organo‐boron based thermally activated delayed fluorescence (TADF) emitters have witnessed outstanding achievements. However, it is still challenging to achieve pure blue color (CIE y < 0.20) along with high efficiencies. To overcome these hurdles, the hyperfluorescence (HF) system suggests a key strategy for future display applications. Here, two TADF host materials, p MDBA‐DI and m MDBA‐DI, and a pure blue multi‐resonance type tert‐butyl substituted TADF fluorescence emitter t ‐Bu‐ν‐DABNA are reported, for efficient HF devices. Among the synthesized TADF sensitized host materials, the m MDBA‐DI HF device exhibits a high external quantum efficiency of 39.1% along with narrow emission with full width at half maximum of 19 nm (CIE y = 0.15). The high device efficiency is mainly attributed to the high molecular orientation factor, enhanced photoluminescence quantum yield, and a good TADF characteristic of t ‐Bu‐ν‐DABNA with efficient Förster energy transfer. Abstract : By using organo‐boron based emitters, an excellent hyperfluorescence (HF) OLED system is designed. As a result, a high external quantum efficiency (EQE) of over 40% and pure blue color with a CIE y coordinate of 0.15 are achieved. Further, a long lifetime (LT50 ) of 440 h with the designed HF systems is reached. Additionally, the detailed parameters for such high EQE values are analyzed.