3 years ago

Prediction of Intramolecular Charge-Transfer Excitation for Thermally Activated Delayed Fluorescence Molecules from a Descriptor-Tuned Density Functional

Prediction of Intramolecular Charge-Transfer Excitation
for Thermally Activated Delayed Fluorescence Molecules from a Descriptor-Tuned
Density Functional
Chao Wang, Qisheng Zhang, Dan Wang, Chao Deng
The reliability of time-dependent density functional theory (TDDFT) for the calculation of the charge-transfer (CT) excitation energy depends on the proportion of the Hartree–Fock (HF) exchange (α) in a hybrid functional. Here, we develop a new descriptor-tuning methodology to determine the optimal α (OHF) in a hybrid PBE functional (PBEα). The conventional transition-density-based descriptors are shown to be inappropriate to measure the degree of CT for our approach because of the functional-dependence. A new functional-independent descriptor K, defined as the negative growth rate of the exciton binding energy upon α, is then developed and found to be highly correlated with the OHF in the PBEα. Applying the so-called K-OHF method, the lowest singlet excitation energy and singlet–triplet energy splitting of various reported thermally activated delayed fluorescence (TADF) materials are successfully reproduced with mean absolute deviations of 0.07 and 0.09 eV, respectively, compared to the carefully measured experimental data. The K-OHF method provides an easy-using way of choosing reliable density functional for the large CT systems.

Publisher URL: http://dx.doi.org/10.1021/acs.jpcc.7b10560

DOI: 10.1021/acs.jpcc.7b10560

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.