Extracting Design Principles for Efficient Thermally Activated Delayed Fluorescence (TADF) from a Simple Four-State Model
Name
Extracting_Design_Principles_for_Efficient_Thermally_Activated_Delayed_Fluorescence__TADF__from_a_Simple_Four-State_Mode_v1.pdf
Description
Submitted version
Size
1.88 MB
Format
Adobe PDF
Checksum (MD5)
2bf87d421fb5a0cac5b6ef2bb8a4570a
Author(s)
de Silva, Piotr
Kim, Changhae Andrew
Zhu, Tianyu
Van Voorhis, Troy
Date Issued
June 2019
Journal
Chemistry of materials
Publisher
American Chemical Society (ACS)
Citation
Silva, Piotr de et al. “Extracting Design Principles for Efficient Thermally Activated Delayed Fluorescence (TADF) from a Simple Four-State Model.” Chemistry of materials 31 (2019): 6995-7006.
Version
Original manuscript
Abstract
We introduce a simple quantum-mechanical model for thermally activated delayed fluorescence (TADF). The Hamiltonian is represented in the basis of four spin-mixed diabatic states representing pure charge transfer (CT) and local excitations (LE). The model predicts that it is possible to realize lowest-lying adiabatic singlet (S1) and triplet (T1) states with a small singlet-triplet gap, differing CT/LE contributions, and appreciable LE component in the S1 state. These characteristics can explain the coexistence of fast T1 → S1 reverse intersystem crossing and S1 → S0 radiative decay in some chromophores. Through the sampling of the parameter space and statistical analysis of the data, we show which parameter combinations contribute the most to the TADF efficiency. We also show that conformational fluctuations of a single model donor-acceptor system sample a significant region of the parameter space and can enhance the TADF rate by almost 3 orders of magnitude. This study provides new guidelines for optimization of TADF emitters by means of electronic structure and conformation engineering.
MIT Department
Massachusetts Institute of Technology. Department of Chemistry
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1021/ACS.CHEMMATER.9B01601
