The design and synthesis of highly efficient deep red (DR) near-infrared (NIR) organic emitting materials with characteristic thermally activated delayed fluorescence (TADF) still remains a great challenge. A strategy was developed to construct TADF solid films strong DR or NIR emission feature. triphenylamine (TPA) quinoxaline-6,7-dicarbonitrile (QCN) were employed as electron donor (D) acceptor (A), respectively, synthesize compound, TPA-QCN. TPA-QCN molecule orange-red in solution dopant...

The design and preparation of metal-free organic materials that exhibit room-temperature phosphorescence (RTP) is a very attractive topic owing to potential applications in optoelectronic devices. Herein, we present facile approach efficient long-lived RTP involving the doping N-phenylnaphthalen-2-amine (PNA) or its derivatives into crystalline 4,4'-dibromobiphenyl (DBBP) matrix. resulting showed strong persistent emission with quantum efficiency approximately 20 % lifetime few more than 100...

Abstract Aggregation‐induced emission (AIE) is commonly observed for propeller‐like luminogens with aromatic rotors and stators. Herein, we report that a coumarin derivative containing seven‐membered aliphatic ring (CD‐7) but no showed typical AIE characteristics, whereas its analogue five‐membered (CD‐5) exhibited an opposite aggregation‐caused quenching (ACQ) effect. Experimental theoretical results revealed large in CD‐7 weakens structural rigidity promotes out‐of‐plane twisting of the...

Quantitative understanding of the photophysical processes is essential for developing novel thermally activated delayed fluorescence (TADF) materials. Taking as an example 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene, a typical TADF-active molecule, we calculated interconversion and decay rates lowest excited singlet triplet states at different temperatures well prompt efficiencies 300 K first-principles level. Our results can reproduce experimentally available data. It found that...

Abstract Aromatic‐imide‐based thermally activated delayed fluorescence (TADF) materials with a twisted donor–acceptor–donor skeleton were efficiently synthesized and exhibited excellent thermal stability high photoluminescence quantum yields. The small Δ E ST value (<0.1 eV) along the clear temperature‐dependent component of their transient (PL) spectra demonstrated TADF properties. Moreover, performance organic light‐emitting diodes in which AI‐Cz AI‐TBCz used as dopants outstanding,...

Abstract The design and preparation of metal‐free organic materials that exhibit room‐temperature phosphorescence (RTP) is a very attractive topic owing to potential applications in optoelectronic devices. Herein, we present facile approach efficient long‐lived RTP involving the doping N ‐phenylnaphthalen‐2‐amine (PNA) or its derivatives into crystalline 4,4′‐dibromobiphenyl (DBBP) matrix. resulting showed strong persistent emission with quantum efficiency approximately 20 % lifetime few...

Thermally activated delayed fluorescence (TADF) is dictated by the properties of lowest singlet (S1) and triplet (T1) excited states. Both small energy difference (ΔEST) large spin–orbit coupling (SOC) between S1 T1 are desired to increase rate for reverse intersystem crossing (RISC). In this work, we investigated ground- excited-state electronic three representative D–(π)–A type TADF molecules in solid phase means a self-consistent quantum-mechanics/embedded-charge (QM/EC) approach, which...

Both the molecular orientation and conformation of thermally activated delayed fluorescence (TADF) emitter molecules that are doped in host matrix crucial to determine performance TADF-based organic light-emitting diodes (OLEDs). However, amorphous packing prohibits observation structural details at atomic accuracy by experimental techniques. Here, using atomistic dynamics simulations, we have uncovered deposition process arrangements a representative donor–acceptor (D–A)-structured TADF...

Abstract The design and synthesis of highly efficient deep red (DR) near‐infrared (NIR) organic emitting materials with characteristic thermally activated delayed fluorescence (TADF) still remains a great challenge. A strategy was developed to construct TADF solid films strong DR or NIR emission feature. triphenylamine (TPA) quinoxaline‐6,7‐dicarbonitrile (QCN) were employed as electron donor (D) acceptor (A), respectively, synthesize compound, TPA‐QCN. TPA‐QCN molecule orange‐red in...

Abstract Aggregation‐induced emission (AIE) is commonly observed for propeller‐like luminogens with aromatic rotors and stators. Herein, we report that a coumarin derivative containing seven‐membered aliphatic ring (CD‐7) but no showed typical AIE characteristics, whereas its analogue five‐membered (CD‐5) exhibited an opposite aggregation‐caused quenching (ACQ) effect. Experimental theoretical results revealed large in CD‐7 weakens structural rigidity promotes out‐of‐plane twisting of the...

Using thermally populated brighter excited states, organic sensors have been developed for wide-range and high temperature sensing in air.

Triplet decay of TADF emitters can be tuned by their molecular structure, leading to the negative temperature dependence emission decay.

Predicting the chemoselectivity of [2 + 2] cyclizations is an important challenge in organic chemistry. Herein, we provided a valuable case for this issue. Density functional theory calculations were performed to systematically study possible mechanisms and origin selectivities N-heterocyclic carbene (NHC)-catalyzed oxidative α-C(sp3)-H activation aliphatic aldehydes cascade cycloaddition with ketimines. The azolium enolate intermediates C═N bond, rather than C═O bond ketimine, revealed be...

Correlation between charge mobility and molecular packing is revealed for the samples fabricated under different processing conditions <italic>via</italic> atomistic simulations.

The rigidity of molecular backbones has an important impact on the energy losses in organic solar cells.

For the first time, side-chain anchoring atoms are found to play an important role in tuning donor/fullerene interfacial arrangements and charge-transfer processes for organic solar cells.

Abstract Four donor–acceptor–donor region isomers (2,3‐TXO‐PhCz, 2,6‐TXO‐PhCz, 2,7‐TXO‐PhCz, and 3,6‐TXO‐PhCz) are designed. The substitution positions of the two PhCz units significantly impact photophysical properties isomers, especially for singlet–triplet energy splitting (Δ E ST ) oscillator strength ( f ). 2,3‐TXO‐PhCz exhibits weak emission due to large steric hindrance units. While 3,6‐TXO‐PhCz all exhibit strong emission. four emitters possess small Δ 0.01–0.24 eV; corresponding...

The ability to accurately diagnose cancer is the cornerstone of early treatment. mitochondria in cells maintain a higher pH and lower polarity relative that normal cells. A probe reports signals only when both conditions are met may provide reliable method for detection with reduced false positives. Here, we construct an AND logic gate fluorescent using mitochondrial microenvironments as inputs. Utilizing hydrolysis coumarin scaffold, generates fluorescence ("ON") high (>7.0) low exist...

High electron mobilities and suppressed π–π aggregation for perylenediimides can be achieved at the same time by properly tailoring dimerization alkylation modes to enhance both intermolecular intramolecular electronic interactions.

Abstract Aromatic‐imide‐based thermally activated delayed fluorescence (TADF) materials with a twisted donor–acceptor–donor skeleton were efficiently synthesized and exhibited excellent thermal stability high photoluminescence quantum yields. The small Δ E ST value (&lt;0.1 eV) along the clear temperature‐dependent component of their transient (PL) spectra demonstrated TADF properties. Moreover, performance organic light‐emitting diodes in which AI‐Cz AI‐TBCz used as dopants outstanding,...

Low energy loss is a prerequisite for organic solar cells to achieve high photovoltaic efficiency. Electron-vibration coupling (i. e., intramolecular reorganization energy) plays crucial role in the photoelectrical conversion and processes. In this Concept article, we summarize our recent theoretical advances on revealing mechanisms at molecular level of A-D-A electron acceptors. We underline importance electron-vibration couplings reducing describe effective design strategies towards low...

We demonstrated the fabrication and study of vertical-stand-type homoepitaxial light-emitting diodes (VLEDs) on a GaN substrate with conical array structures. The arrays were formed N-face surface using size-controllable polystyrene nanosphere as etch mask. 20-mA output power VLEDs flat backside, truncated cone, cone improved by magnitudes 16.5%, 66.8%, 118.5%, respectively, compared that conventional planar configuration LEDs. These improvements could be attributed to increased direct...