Hi All,

We will have a visit of postdoc candidate next Monday. The abstract of the talk is pasted below. Please let me know if you want to meet with her and/or have a lunch (12pm-1:30pm) on Monday.

Cheers,

Dennis

Accurate treatment of charge-transfer excitations and thermally activated delayed fluorescence using the particle-particle random phase approximation

Abstract: Thermally-activated delayed fluorescence (TADF) is a mechanism that increases the efficiency of light emission in organic light-emitting diodes by harnessing both singlet and triplet excitons. TADF is facilitated by a small energy difference between the first singlet (S₁) and triplet (T₁) excited states [DE(ST)], which is minimized by spatial separation of the donor and acceptor moieties. The resultant charge-transfer (CT) excited states are difficult to model using semilocal exchange-correlation (xc) functionals combined with time-dependent density functional theory because of the delocalization error present in these approximate methods. In this talk I will review approaches to model CT transitions in TADF emitters and introduce the results from the particle-particle random phase approximation (pp-RPA). The pp-RPA is able to capture CT states and accurately reproduce excitation energies which is attributed to the consistent treatment of both ground and excited states. Qualitative characterization of excited states as CT or locally excited, in comparison with experiment, and interesting structural features of TADF molecules will be discussed as well.

Speaker: Rachael Al-Saadon