Dual Emission through Thermally Activated Delayed Fluorescence and Room-Temperature Phosphorescence, and Their Thermal Enhancement via Solid-State Structural Change in a Carbazole-Quinoline Conjugate
Dual Emission through Thermally Activated Delayed Fluorescence and Room-Temperature Phosphorescence, and Their Thermal Enhancement via Solid-State Structural Change in a Carbazole-Quinoline Conjugate
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DOI：
10.1021/acs.jpclett.8b00937
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发表时间：
2018-06-07
影响因子：
5.7
通讯作者：
Ray, Debdas
中科院分区：
文献类型：
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作者：
Bhattacharjee, Indranil;Acharya, Nirmalya;Ray, Debdas
单组分有机双发光材料的出现为白色发光二极管（WLED）和生物检测带来了巨大的希望，因为它具有覆盖可见光谱的宽发射。在这里，我们展示了关于咔唑-喹啉缀合物（CQ）的双发射的实验研究，该缀合物既通过从较高三重态（T-2）到单重态（S-1）的反向系间穿越（rISC）表现出热激活延迟荧光（TADF），又表现出室温磷光（RTP）由于T-2和Si之间的低能隙，从最低三重态（T-1），以及T-1和T-2的能量接近我们在热效应中发现，随着温度升高到100摄氏度，双重特征的强度增强，这可以通过热致结构变化（TISC）机制来解释，该机制补偿了由于高温下的非辐射跃迁而导致的发射损失。这种性质，除了其增强的TADF和磷光衰减速率（类似于100 ℃时的10（7）s（-1）和10（1）s（-1））之外，对于高效率LED将具有很大的希望。
The emergence of single-component organic dual light emitters holds great promise for white light-emitting diodes (WLEDs) and biological detection due to the involvement of broad emission covering visible spectrum. Here we show experimental studies on dual emission of carbazole-quinoline conjugate (CQ) that exhibits both thermally activated delayed fluorescence (TADF) via reverse intersystem crossing (rISC) from the higher-lying triplet state (T-2) to the singlet state (S-1) and room-temperature phosphorescence (RTP) from the lowest triplet state (T-1) due to low energy gap between T-2 and Si, and energetic proximity of T-1 with T-2. We found in thermal effect that the intensity of the dual features is enhanced with increasing temperatures up to 100 degrees C, which can be explained by a thermal-induced structural change (TISC) mechanism that compensates the emission losses due to nonradiative transitions at elevated temperatures. This property, in addition to its enhanced TADF and phosphorescence decay rates (similar to 10(7) s(-1) and 10(1) s(-1)) at 100 degrees C, would have great promise for high-efficiency LEDs.