Thermally Activated Delayed Fluorescence from Azasiline Based Intramolecular Charge-Transfer Emitter (DTPDDA) and a Highly Efficient Blue Light Emitting Diode

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• 作者：Jin Won Sun ; Jang Yeol Baek ; Kwon-Hyeon Kim ; Chang-Ki Moon ; Jeong-Hwan Lee ; Soon-Ki Kwon ; Yun-Hi Kim ; Jang-Joo Kim
• 刊名：Chemistry of Materials
• 出版年：2015
• 出版时间：October 13, 2015
• 年：2015
• 卷：27
• 期：19
• 页码：6675-6681
• 全文大小：417K
• ISSN：1520-5002

文摘

For electroluminescence with delayed fluorescence, the azasiline unit has been introduced for the first time as a donor in a thermally activated delayed fluorescence (TADF) material. The TADF material (DTPDDA) shows strong intramolecular charge transfer (CT) character with large spatial separation with the acceptor of triazine leading to narrow splitting of singlet and triplet excited states for the efficient reverse intersystem crossing (RISC). A blue organic light emitting diode (OLED) based on DTPDDA not only displays deep blue in the Commission Internationale de L鈥橢clairage (CIE) coordinates of (0.149, 0.197) but also exhibits a high external quantum efficiency (EQE) of 22.3% which is the highest value ever reported for a blue fluorescent OLED. Theoretical prediction based on transient photoluminescence (PL) and optical simulation result agrees well with the achieved EQE indicating the successful conversion of triplet excitons to singlet in the blue fluorescent OLED by using DTPDDA.