Purely organic materials showing room temperature phosphorescence (RTP) and ultralong RTP (OURTP) have recently attracted much attention. However, it is challenging to integrate circularly polarized luminescence (CPL) into RTP/OURTP. Here, we show a strategy to realize CPL‐active OURTP (CP‐OURTP) by binding an achiral phosphor group directly to the chiral center of an ester chain. Engineering of this flexible chiral chain enables efficient chirality transfer to carbazole aggregates, resulting in strong CP‐OURTP with a lifetime of over 0.6 s and dissymmetry factor of 2.3×10−3 after the conformation regulation upon photo‐activation. The realized CP‐OURTP is thus stable at room temperature but can be deactivated quickly at 50 °C to CP‐RTP with high CPL stability during the photo‐activation/thermal‐deactivation cycles. Based on this extraordinary photo/thermal‐responsive and highly reversible CP‐OURTP/RTP, a CPL‐featured lifetime‐encrypted combinational logic device has been successfully established.

Developing high-efficient afterglow from metal-free organic molecules remains a formidable challenge due to the intrinsically spin-forbidden phosphorescence emission nature of organic afterglow, and only a few examples exhibit afterglow efficiency over 10%. Here, we demonstrate that the organic afterglow can be enhanced dramatically by thermally activated processes to release the excitons on the stabilized triplet state (T 1 *) to the lowest triplet state (T 1) and to the singlet excited state (S 1) for spin-allowed emission. Designed in a twisted donor-acceptor architecture with small singlet-triplet splitting energy and shallow exciton trapping depth, the thermally activated organic afterglow shows an efficiency up to 45%. This afterglow is an extraordinary tri-mode emission at room temperature from the radiative decays of S 1 , T 1 , and T 1 *. With the highest afterglow efficiency reported so far, the tri-mode afterglow represents an important concept advance in designing high-efficient organic afterglow materials through facilitating thermally activated release of stabilized triplet excitons.

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Among five methods in predicting intersystem crossing of TADF molecules, NTO similarity and n-orbital analyses based on the T1 structure were found to be efficient with low computational costs and high accuracy.

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Benefitting from narrow band gap nonfullerene acceptors, continually increasing power conversion efficiency (PCE) endows organic solar cells (OSCs) with great potential for commercial application. Fabricating high-performance OSCs with potential for large-scale coating and nonhalogenated solvent processing is a necessity. Herein, we have proposed the use of nonhalogenated solvents combined with high-temperature blade coating to prepare a PM6 (poly­[(2,6-(4,8-bis­(5-(2-ethylhexyl-3-fluoro)­thiophen-2-yl)­benzo­[1,2-b:4,5-b′]­dithiophene))-alt-(5,5-(1′,3′-di-2-thienyl-5′,7′-bis­(2-ethylhexyl)­benzo­[1′,2′-c:4′,5′-c′]­dithiophene-4,8-dione)]):Y6 (2,2′-((2Z,2′Z)-((12,13-bis­(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]­thiadiazolo­[3,4-e]­thieno­[2″,3′′:4′,5′]­thieno­[2′,3′:4,5]­pyrrolo­[3,2-g]­thieno­[2′,3′:4,5]­thieno­[3,2-b]­indole-2,10-diyl)­bis­(methanylylidene))­bis­(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene)))­blend active layer. The resultant OSCs deliver a PCE of 15.51% when the PM6:Y6 active layer is blade-coated at 90 °C in nonhalogenated o-xylene (o-XY) host solvent containing 1,2-dimethylnaphthalene (DMN) additive. It is found that high-temperature blade coating and nonhalogenated solvent additive DMN can suppress excessive aggregation of Y6 and enhance the crystallinity of PM6 and Y6 by regulating the dynamic process of active layer formation. Finally, an optimized blend morphology with nanofibrous phase separation and enhanced crystallinity are achieved for the PM6:Y6 active layer prepared with high-temperature blade coating and nonhalogenated o-XY:DMN solvents, which not only shortens the film-drying time but also leads to increased charge generation, transport, and collection efficiency. The 1.00 cm2 OSCs prepared with high-temperature blade coating and nonhalogenated solvents exhibit a high PCE of 13.87%. This approach shows great potential for large-area fabrication of OSCs.

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