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Comprehensive Summary: Deep ultraviolet (UV) photodetectors have important applications in the industrial and military fields. However, little research has been reported on organic phototransistors (OPTs) in the deep ultraviolet range. Here, a novel organic semiconductor containing a small torsion angle and low π‐conjugation 2,2':5',2"‐terthiophene groups, oF‐PTTTP, is designed and synthesized, which exhibits high carrier mobility and unique deep ultraviolet response. Accordingly, an OPT based on oF‐PTTTP single crystal shows high responsivity to deep‐UV light. The photodetectors achieve high photoresponsivity (R) of 857 A/W and detectivity (D*) of 3.2×1015 Jones under 280 nm light illumination (only 95 nW·cm–2). To the best of our knowledge, 280 nm is the deepest detection wavelength reported for organic phototransistors and this work presents a new molecule design concept for organic phototransistors with deep‐UV detection. [ABSTRACT FROM AUTHOR]

The disordered chain arrangement of polymer dielectrics has complex both internal and external effects on system performance, which generally stimulates the weak acquisition and grain boundaries of vapor‐deposited organic small molecule films (VDOSMFs) with thermally activated charge transport. As a result, achieving "band‐like" transmission of VDOSMs on polymer dielectrics is attempting to prove to be a major challenge. Three types of bi‐polymer dielectrics are developed to modulate charge transport from thermally activated mode to "band‐like" transport at the interfacial level. The bottom consisting of a polyimide layer is critical to interfacial modulation, which shows the selectively binding capability with up‐dielectric layers to realize the modulation of charge transport, as corroborated by interface characterization and density functional‐based tight‐binding calculation. The findings provide an effective strategy for modulating the charge transport through polymer dielectric engineering and also recommend a podium to further comprehend the electrical characteristics of small molecules in organic thin‐film transistors. [ABSTRACT FROM AUTHOR]

Phase‐change semiconductor is one of the best candidates for designing nonvolatile memory, but it has never been realized in organic semiconductors until now. Here, a phase‐changeable and high‐mobility organic semiconductor (3,6‐DATT) is first synthesized. Benefiting from the introduction of electrostatic hydrogen bond (S···H), the molecular conformation of 3,6‐DATT crystals can be reversibly modulated by the electric field and ultraviolet irradiation. Through experimental and theoretical verification, the tiny difference in molecular conformation leads to crystalline polymorphisms and dramatically distinct charge transport properties, based on which a high‐performance organic phase‐change memory transistor (OPCMT) is constructed. The OPCMT exhibits a quick programming/erasing rate (about 3 s), long retention time (more than 2 h), and large memory window (i.e., large threshold voltage shift over 30 V). This work presents a new molecule design concept for organic semiconductors with reversible molecular conformation transition and opens a novel avenue for memory devices and other functional applications. [ABSTRACT FROM AUTHOR]

Organic semiconductors with combinative high carrier mobility and efficient solid‐state emission are full of challenges but urgently pursued for developing new emerging optoelectronics. Herein, by delicately regulating the crystal packing of an anthracene‐based molecular crystal via terminal tert‐butylation, we developed a superior high mobility emissive molecule, 2,6‐di(6‐tert‐butylnaphthyl)anthracene (TBU‐DNA). The unique "slipped herringbone" packing motif of TBU‐DNA enables its appropriate exciton‐exciton coupling and electron‐phonon coupling, thus resulting in remarkably high solid‐state emission (photoluminescence quantum yield, ΦF≈74.9 %) and efficacious charge transport (carrier mobility, μ=5.0 cm2 V−1 s−1). Furthermore, OLETs based on TBU‐DNA show an external quantum efficiency (EQE) of 1.8 %, which is among the highest EQE values for single component OLETs reported till now. This work presents a crystal engineering strategy via exquisite molecular design to realize high mobility emissive organic semiconductors. [ABSTRACT FROM AUTHOR]

Organic semiconductors with combinative high carrier mobility and efficient solid‐state emission are full of challenges but urgently pursued for developing new emerging optoelectronics. Herein, by delicately regulating the crystal packing of an anthracene‐based molecular crystal via terminal tert‐butylation, we developed a superior high mobility emissive molecule, 2,6‐di(6‐tert‐butylnaphthyl)anthracene (TBU‐DNA). The unique "slipped herringbone" packing motif of TBU‐DNA enables its appropriate exciton‐exciton coupling and electron‐phonon coupling, thus resulting in remarkably high solid‐state emission (photoluminescence quantum yield, ΦF≈74.9 %) and efficacious charge transport (carrier mobility, μ=5.0 cm2 V−1 s−1). Furthermore, OLETs based on TBU‐DNA show an external quantum efficiency (EQE) of 1.8 %, which is among the highest EQE values for single component OLETs reported till now. This work presents a crystal engineering strategy via exquisite molecular design to realize high mobility emissive organic semiconductors. [ABSTRACT FROM AUTHOR]

Integrating high charge‐carrier mobility and low‐threshold lasing action in an organic semiconductor is crucial for the realization of an electrically pumped laser, but remains a great challenge. Herein, we present an organic semiconductor, named as 2,7‐di(2‐naphthyl)‐9H‐fluorene (LD‐2), which shows an unexpected high charge‐carrier mobility of 2.7 cm2 V−1 s−1 and low‐threshold lasing characteristic of 9.43 μJ cm−2 and 9.93 μJ cm−2 and high‐quality factor (Q) of 2131 and 1684 at emission peaks of 420 and 443 nm, respectively. Detailed theoretical calculations and photophysical data analysis demonstrate that a large intermolecular transfer integral of 10.36–45.16 meV together with a fast radiative transition rate of 8.0×108 s−1 are responsible for the achievement of the superior integrated optoelectronic properties in the LD‐2 crystal. These optoelectronic performances of LD‐2 are among the highest reported low‐threshold lasing organic semiconductors with efficient charge transport, suggesting its promise for research of electrically pumped organic lasers (EPOLs). [ABSTRACT FROM AUTHOR]

Integrating high charge‐carrier mobility and low‐threshold lasing action in an organic semiconductor is crucial for the realization of an electrically pumped laser, but remains a great challenge. Herein, we present an organic semiconductor, named as 2,7‐di(2‐naphthyl)‐9H‐fluorene (LD‐2), which shows an unexpected high charge‐carrier mobility of 2.7 cm2 V−1 s−1 and low‐threshold lasing characteristic of 9.43 μJ cm−2 and 9.93 μJ cm−2 and high‐quality factor (Q) of 2131 and 1684 at emission peaks of 420 and 443 nm, respectively. Detailed theoretical calculations and photophysical data analysis demonstrate that a large intermolecular transfer integral of 10.36–45.16 meV together with a fast radiative transition rate of 8.0×108 s−1 are responsible for the achievement of the superior integrated optoelectronic properties in the LD‐2 crystal. These optoelectronic performances of LD‐2 are among the highest reported low‐threshold lasing organic semiconductors with efficient charge transport, suggesting its promise for research of electrically pumped organic lasers (EPOLs). [ABSTRACT FROM AUTHOR]

Molecule design of organic semiconductors (OSCs) for eliminating photoresponse and maintaining high charge mobility concurrently is beneficial to realize intrinsically photostable and high‐performance organic field‐effect transistors (OFETs), which has never been reported. Here, a novel organic semiconductor TFP‐TT‐TPA with a centrosymmetric structure is synthesized. Remarkably, OFETs with TFP‐TT‐TPA show negligible photoresponse under light intensity up to 170.4 mW cm−2 (higher than sunlight intensity, about 138 mW cm−2), which ensures that the devices can work stably under sunlight. Through the single‐crystal structure and exciton dynamics analysis, it is found that the specific structure design can make strong intermolecular D–A interaction that occurs in the aggregate state, which facilitates the process of exciton quenching and thus enables the photostable OFETs. This study provides a new strategy for the design of organic semiconductors with intrinsic photostability and the construction of photostable organic optoelectronic devices for applications in light environment. [ABSTRACT FROM AUTHOR]

Organic phototransistors (OPTs) are playing an indispensable role in organic optoelectronics, which greatly show their promising application in optical communication, video imaging, missile guidance, and night vision. However, because the thermally activated mode dominated for thin‐film devices leads to a sharp drop in mobility at low temperatures, until now, most of the studies about OPTs are performed at room temperature, severely hindering their further potential optoelectronic application over a broad range of temperatures, especially at low temperature environment. In this work, the optoelectronic properties of a small molecule (2,6‐diphenylanthracene, DPA) based OPTs with band‐like transport are studied at low temperatures. The devices exhibit outstanding optoelectronic properties in terms of mobility (2.6 cm2 V−1 s−1), on/off ratio (≈104), detectivity (1013 Jones), and external quantum efficiency (2500%) even at 150 K, which is superior to the performance of devices with thermally activated mode. In addition, the organic photodetector at low temperatures is also fabricated. Our results demonstrate that organic π‐conjugated DPA small‐molecule has great potential in low‐temperature application. [ABSTRACT FROM AUTHOR]

Keywords: Charge Transport; Crystal Engineering; Light Emission; Molecular Crystals; Organic Semiconductor EN Charge Transport Crystal Engineering Light Emission Molecular Crystals Organic Semiconductor 1 1 1 11/03/22 20221107 NES 221107 B An anthracene-based molecular crystal b with a unique "slipped herringbone" packing motif was developed by crystal engineering through terminal I tert i -butylation. Appropriate exciton-exciton coupling/electron-phonon coupling originating from the unique crystal packing induces a remarkably strong solid-state emission and efficient charge transport, as reported by Wenping Hu et al. in their Research Article (e202206825). Appropriate exciton-exciton coupling/electron-phonon coupling originating from the unique crystal packing induces a remarkably strong solid-state emission and efficient charge transport, as reported by Wenping Hu et al. in their Research Article (e202206825). [Extracted from the article]