文献类型：期刊文献

英文题名：Theoretical insights into long-range coupling of electron-hole pairs in TCTA -PO-T2T exciplex

作者：Jin, Yichao[1];Lu, Zhaoyue[1];Wang, Xiao[1];Tang, Zongkai[1];Mu, Haichuan[1]

机构：[1]East China Univ Sci & Technol, Sch Phys, Shanghai 200237, Peoples R China

年份：2024

卷号：130

外文期刊名：ORGANIC ELECTRONICS

收录：;EI(收录号：20240104086);WOS:【SCI-EXPANDED(收录号:WOS:001241517300001)】；

语种：英文

外文关键词：Exciplex; Intermolecular charge transfer; Charge transfer index; D -A distance; Excited states

摘要：This work reports theoretical investigations concerning long-range coupling of electron -hole pairs in spatially separated exciplex (SSE) systems via Density Functional Theory and Time -Dependent Density Functional Theory. Based on TCTA-PO-T2T parent exciplex, where 4,4 ' ,4 '' -Tris(carbazol-9-yl)triphenylamine (TCTA) serves as donor (D) and 2,4,6-Tris[3-(diphenylphosphinyl)phenyl]-1,3,5-triazine (PO-T2T) as acceptor (A), SSEs are constructed by intentionally tuning the D -A distance. The calculation results demonstrate that all SSEs, even if the D -A distance is over 14 & Aring;, exhibit the clear and strong charge transfer character in terms of D CT , q CT , and t indexes. As the D -A distance increases, the energy gap of SSEs is increased, resulting in the blueshift of emission spectra. Calculation and experiment results show a good consistency, indicating that our model could well describe SSEs. Meanwhile, the reduced energy gap between CT and 3 LE and more degenerate states could boost reverse intersystem crossing via vibronic coupling and hyperfine coupling, eventually improving the electroluminescent performance of SSEs. Our study suggests that manipulation of relative energy alignment via controlling D -A distance not only promotes the properties of exciplexes, but also offers guidance for designing thermally activated delayed fluorescence emitters through -space charge transfer.