红荧烯类似物C38H24S2的单线态分裂过程

Singlet exciton fission in rubrene analogueue C38H24S2

单线态分裂可以规避光电转换中的能量损失,从而提高光电转换效率。利用飞秒时间分辨瞬态吸收光谱技术研究了在不同激发条件下溶于甲苯溶液的红荧烯类似物C38H24S2的激发态动力学过程。在550 nm和365 nm光激发下,激发单线态与基态分子发生碰撞,分别在8.2 ps和3 ps时产生了关联的三线态激子对。但在550 nm光激发下未观察到独立的三线态激子信号;而在365 nm光激发下,关联的三线态激子对的诱导吸收信号发生了转移,在探测波长550 nm附近观察到独立的三线态激子的吸收。在460 nm光激发下,利用奇异值分解的方法在瞬态吸收光谱中观察到了单线态分裂过程。

Singlet fission can circumvent energy-loss and improve the photoelectric conversion efficiency of solar cells.The excited state dynamics of rubrene analogueue C38H24S2 in toluene solution under different excitation conditions is investigated using femtosecond time-resolved transient absorption spectroscopy.Under the excitation of 550 nm and 365 nm,the excited singlet excitons collide with ground state molecules,and the correlated triplet pairs are generated at 8.2 ps and 3 ps,respectively.However,no independent triplet state signal is observed with the excitation wavelength of 550 nm.While under the excitation of 365 nm,the induced absorption signal of the triplet pair shifts,and the absorption of independent triplet exciton is observed around the detection wavelength of 550 nm.Besides,the singlet fission is observed by using the singular value decomposition method in the transient absorption spectrum with the excitation wavelength of 460 nm.