Tailoring Excited-State Properties and Electroluminescence Performance of Donor Acceptor Molecules through Tuning the Energy Level of the Charge-Transfer State
Tailoring Excited-State Properties and Electroluminescence Performance of Donor Acceptor Molecules through Tuning the Energy Level of the Charge-Transfer State
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通过调节电荷转移态的能级来定制供体受体分子的激发态特性和电致发光性能
DOI：
10.1021/acs.jpcc.5b03996
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发表时间：
2015
影响因子：
3.7
通讯作者：
Ma Yuguang
中科院分区：
文献类型：
--
作者：
Yao Liang;Pan Yuyu;Tang Xiangyang;Bai Qing;Shen Fangzhong;Li Feng;Lu Ping;Yang Bing;Ma Yuguang
设计并合成了三种不同结构的给体-受体（D-A）化合物（PTZ-10-AnP，PTZ-10 P-AnP，PTZ-3-AnP）。结构的变化，主要是指扭转角和D和A之间的距离，导致这些化合物的CT水平的位置显着不同。PTZ-10-AnP的CT态处于最低激发态，而PTZ-10 P-AnP的CT态处于较高激发态。对于PTZ-3-AnP，CT能量接近于局部π-π* 激发态，杂化的局部和电荷转移（HLCT）态占主导地位。这些化合物的光物理实验数据表明，电荷转移（CT）态的能级对给体-受体（D-A）化合物的发射态性质起着决定性的作用。此外，PTZ-3-AnP器件的激子利用效率超过了自旋统计的极限，这启发了在荧光有机发光二极管（OLED）中捕获三重态激子的分子设计。
Three donor–acceptor (D–A) compounds (PTZ-10-AnP, PTZ-10P-AnP, and PTZ-3-AnP) were designed and synthesized through linking the same D and A units with different architectures. The structural change, mainly referring to the torsion angle and distance between D and A, gives rise to the significantly different CT level positions for these compounds. The CT state of PTZ-10-AnP locates at the lowest excited state, while that of PTZ-10P-AnP stays at the higher excited state. For PTZ-3-AnP, the CT energy is close to that of the locally π–π* excited state, and a hybridized local and charge-transfer (HLCT) state dominates the S1state. Photophysical experiment data of these compounds demonstrate that the energy level of the charge-transfer (CT) state plays a decisive role in the emissive state properties of donor–acceptor (D–A) compounds. In addition, the exciton utilization efficiency of the PTZ-3-AnP device exceeds the limit of the spin statistics, which enlightens the molecular design toward harvesting triplet excitons in fluorescent organic light-emitting diodes (OLEDs).