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Precise fabrication of organic micro/nanostructures with regular morphology has gained a considerable concern in developing high‐performance optoelectronic devices, which is still a huge challenge to realize tunable morphology without the dependence on molecule packing arrangement. Herein, a thermodynamic/kinetic controlled self‐assembly for triphenylene‐7,7,8,8‐tetracyanoquinodimethane (TP‐TCNQ) cocrystal, with well‐defined microwires and microplates based on the same crystal structure, is proposed. With the low solution concentration of C = 5 mm, the comparable growth rates along [011] driven by π–π interaction and along [100] driven by charge‐transfer (CT) interaction facilitate the formation of thermodynamically favored shape of microplates. In contrast, the prominent CT interaction along [100] leads to the construction of microwires at kinetic state under high‐concentration solution of C = 10 mm. Furthermore, the prepared TP‐TCNQ microwires and microplates demonstrate isotropic photonic transmissions with the low optical loss coefficient of 0.033 and 0.042 dB µm−1, respectively. This strategy provides a novel avenue to finely construct the organic microcrystals with desired morphology for potential optoelectronics. [ABSTRACT FROM AUTHOR]

Organic photothermal cocrystals, integrating the advantages of intrinsic organic cocrystals and the fascinating photothermal conversion ability, hold attracted considerable interest in both basic science and practical applications, involving photoacoustic imaging, seawater desalination, and photothermal therapy, and so on. However, these organic photothermal cocrystals currently suffer individual cases discovered step by step, as well as the deep and systemic investigation in the corresponding photothermal conversion mechanisms is rarely carried out, suggesting a huge challenge for their further developments. Therefore, it is urgently necessary to investigate and explore the rational design and synthesis of high‐performance organic photothermal cocrystals for future applications. This review first and systematically summarizes the organic photothermal cocrystal in terms of molecular classification, the photothermal conversion mechanism, and their corresponding applications. The timely interpretation of the cocrystal photothermal effect will provide broad prospects for the purposeful fabrication of excellent organic photothermal cocrystals toward great efficiency, low cost, and multifunctionality. [ABSTRACT FROM AUTHOR]

Organic near‐infrared (NIR) emissive materials integrating the intrinsic NIR light advantages and organic semiconductor characters have generated immense scientific interest in fundamental science and practical application, including optical communications, night vision, surveillance, and biomedical applications. Nevertheless, the intrinsic energy gap law engenders a huge challenge to simultaneously meet longer emission wavelength and higher luminescence efficiency for organic NIR emitters. Herein, it is suggested that the purposefully molecular design and crystal engineering for novel organic NIR materials are urgently studied and explored. Herein, recent advances in novel organic NIR materials, mainly focusing on the hybridized local and charge transfer (HLCT) compounds, thermally activated delayed fluorescence (TADF) emitters, CT cocrystals, neutral π‐radicals, and excited‐state intramolecular proton transfer (ESIPT)‐active materials, are summarized. It is hoped that this perspective can afford a new insight into the fine design and synthesis of the desired organic NIR emitters. [ABSTRACT FROM AUTHOR]

Near‐infrared (NIR) organic solid‐state lasers play an essential role in applications ranging from laser communication to infrared night vision, but progress in this area is restricted by the lack of effective excited‐state gain processes. Herein, we originally proposed and demonstrated the cascaded occurrence of excited‐state intramolecular proton transfer for constructing the completely new energy‐level systems. Cascading by the first ultrafast proton transfer of <430 fs and the subsequent irreversible second proton transfer of ca. 1.6 ps, the stepwise proton transfer process favors the true six‐level photophysical cycle, which supports efficient population inversion and thus NIR single‐mode lasing at 854 nm. This work realizes longest wavelength beyond 850 nm of organic single‐crystal lasing to date and originally exploits the cascaded excited‐state molecular proton transfer energy‐level systems for organic solid‐state lasers. [ABSTRACT FROM AUTHOR]

Near‐infrared (NIR) organic solid‐state lasers play an essential role in applications ranging from laser communication to infrared night vision, but progress in this area is restricted by the lack of effective excited‐state gain processes. Herein, we originally proposed and demonstrated the cascaded occurrence of excited‐state intramolecular proton transfer for constructing the completely new energy‐level systems. Cascading by the first ultrafast proton transfer of <430 fs and the subsequent irreversible second proton transfer of ca. 1.6 ps, the stepwise proton transfer process favors the true six‐level photophysical cycle, which supports efficient population inversion and thus NIR single‐mode lasing at 854 nm. This work realizes longest wavelength beyond 850 nm of organic single‐crystal lasing to date and originally exploits the cascaded excited‐state molecular proton transfer energy‐level systems for organic solid‐state lasers. [ABSTRACT FROM AUTHOR]

Abstract: Anisotropic organic molecular construction and packing are crucial for the optoelectronic properties of organic crystals. Two‐dimensional (2D) organic crystals with regular morphology and good photon confinement are potentially suitable for a chip‐scale planar photonics system. Herein, through the bottom‐up process, 2D halogen‐bonded DPEpe‐F4DIB cocrystals were fabricated that exhibit an asymmetric optical waveguide with the optical‐loss coefficients of RBackward=0.0346 dB μm−1 and RForward=0.0894 dB μm−1 along the [010] crystal direction, which can be attributed to the unidirectional total internal reflection caused by the anisotropic molecular packing mode. Based on this crystal direction‐oriented asymmetric photon transport, these as‐prepared 2D cocrystals have been demonstrated as a microscale optical logic gate with multiple input/out channels, which will offer potential applications as the 2D optical component for the integrated organic photonics. [ABSTRACT FROM AUTHOR]

Abstract: Anisotropic organic molecular construction and packing are crucial for the optoelectronic properties of organic crystals. Two‐dimensional (2D) organic crystals with regular morphology and good photon confinement are potentially suitable for a chip‐scale planar photonics system. Herein, through the bottom‐up process, 2D halogen‐bonded DPEpe‐F4DIB cocrystals were fabricated that exhibit an asymmetric optical waveguide with the optical‐loss coefficients of RBackward=0.0346 dB μm−1 and RForward=0.0894 dB μm−1 along the [010] crystal direction, which can be attributed to the unidirectional total internal reflection caused by the anisotropic molecular packing mode. Based on this crystal direction‐oriented asymmetric photon transport, these as‐prepared 2D cocrystals have been demonstrated as a microscale optical logic gate with multiple input/out channels, which will offer potential applications as the 2D optical component for the integrated organic photonics. [ABSTRACT FROM AUTHOR]

Semiconductor quantum dots (QDs), traditionally based on lead or cadmium, are the promising fluorescent materials for use in bright illumination, detecting and display technology. However, the toxicity of these QDs materials traditionally based on heavy metal cause great concern to human health and environmental protection. Thus, carbon dots from pure natural materials with low toxicity and extensive resources soon raised attention. Here, we introduce a pure physical method to extract carbon dots from the seed's inner skin of torreya grandis which is a Chinese endemic plant widely grown in the southeastern China, such as in Jiangsu, Fujian and Zhejiang Provinces. These carbon dots come from natural plants and only cyclohexane and ethanol with hypotoxicity are used in extracting process to ensure the low toxicity of our material. Besides, we also fabricated light-emitting diodes based on the extracted light-emitting carbon dots. The emission peak of our devices appears at 438 nm with Commission International de I'Eclairage (CIE) color coordinate (0.177, 0.075). [Display omitted] • Carbon dots with blue photoluminescence at a peak of 431 nm was reported. • The carbon dots were collected from a pure natural plant – Torreya grandis. • Centrifuge was applied to extract the carbon dots with only ethanol and cyclohexane. • Devices with blue emission at a peak of 438 nm and with the FWHM of about 45 nm are fabricated. [ABSTRACT FROM AUTHOR]

Organic single crystals have attracted great attention for solid‐state lasers owing to their smooth morphologies with inherent optical microcavity, ordered molecular packing mode with minimized defects density, and high photoluminescence quantum efficiency. However, the organic single‐crystal lasers, including whispering‐gallery‐mode (WGM) lasers with nondirectional emission and Fabry–Perot (F–P) lasers with inherent high‐lasing threshold, cannot achieve state‐of‐the‐art performance. Herein, the hierarchical self‐assembly of organic single‐crystal heterostructures made from cube‐shaped microdisks with optical gain and microwires with optical waveguide characteristics is demonstrated, which realize the unidirectional WGM laser action with a low‐lasing threshold of ≈600 nJ cm−2. The lattice mismatch rate principle contributes to the growth of these single‐crystal organic heterostructures. More significantly, the waveguide‐coupled WGM microcavity with a coupling coefficient of 28.8% proves that the unidirectional outcoupling of the single‐crystal WGM lasers from the single‐crystal wire waveguides is achieved. The results will pave an alternative avenue for high‐performance organic single‐crystal lasers. [ABSTRACT FROM AUTHOR]

Textile‐based generators that can convert low‐grade energy from the human body or environment into sustainable electricity have generated immense scientific interest in self‐powered wearable applications. However, their low power density and environmental suitability have extremely restricted their portable applications in complex and mutable environments. Herein, an asymmetric sandwich structure between molybdenum disulfide (MoS2)‐carbonized silks (MCs) and MoS2/MXene–Cottons (MMCs) to construct efficient thermo–hydroelectric generators (THEGs) that synergistically harvest heat‐moisture energy to generate considerable electricity is rationally designed. Notably, the large surface area of MoS2/MXene van der Waals heterojunctions (vdWhs) enables efficient charge collection, and the vertical MoS2 nanosheet arrays supply abundant nanochannels for a highly efficient hydration effect, generating an output power density of 32.26 µW cm−2 after wetting with deionized water. Combined with the sensitive temperature recognition ability with a Seebeck coefficient of 23.5 µV K−1, the application possibilities of these prepared THEGs in the mutual conversion of fingertip temperature/language, and the monitoring of the human physiological state is foresee. [ABSTRACT FROM AUTHOR]

Desalination and power generation through solar energy harvesting is a crucial technology that can effectively address freshwater shortages and energy crises. However, owing to the complexity of the actual water environment, the thermal output capability of the photothermal material and the functional integration of the evaporation system need urgent improvement, to obtain high‐quality fresh water and sufficient electricity. Herein, a 2D/2D cesium tungsten bronze/copper sulfide (2D/2D Cs0.32WO3/CuS) nano‐heterojunction is developed and it is loaded into a cellulose‐based hybrid hydrogel to construct a multifunctional evaporator. Benefiting from the more nonradiative recombination centers from deep‐level defects, as well as shorter carrier migration distances and higher redox potentials in the Cs0.32WO3/CuS nano‐heterojunction, this evaporator has a significant improvement in thermal output capacity, enabling both super‐efficient seawater evaporation (4.22 kg m−2 h−1) and photodegradation of organic pollutants (removal rate ≈ 99%). Moreover, the evaporator exhibits long‐term stability and sustainable self‐cleaning property against salt accumulation. Remarkably, the thermoelectric module based on the Cs0.32WO3/CuS nano‐heterojunction shows promising electricity generation performance (4.85 W m−2), which can power small appliances durably and stably, exceeding previously reported similar devices. This 2D/2D heterojunction‐based solar evaporation system will provide a more reliable solution for efficient and sustainable freshwater‐electricity co‐generation in resource‐limited areas. [ABSTRACT FROM AUTHOR]

Abstract: Organic cocrystals formed with two or more different molecules through intermolecular noncovalent interactions, such as π–π interaction and hydrogen/halogen bonds, have received increasing attention due to their promising applications in organic optoelectronics. For organic photonics and electronics, the growth morphology of organic micro/nanocrystals coupled with their shape and emission color is of great importance. In this study, using a “cocrystal” approach, the organic microcrystals can be modulated from the yellow‐emissive polyhedral microcrystals of 1,4‐bis (4‐cyanostyryl) benzene (p‐BCB) to the sky‐blue‐emissive microwires of p‐BCB:1,4‐diiodo tetrafluorobenzene (p‐BCB:DIFB), which are self‐assembled in solution at room temperature. Additionally, with the formation of the cocrystals, the radiative decay (kr) rate of these organic microcrystals is enhanced from 0.04 to 0.12 ns−1, which is attributed to the absence of excimers in the organic cocrystals. Therefore, this “cocrystal” approach can simultaneously tune the emission color, morphology, and molecular packing mode of these as‐prepared organic microcrystals, which can contribute to the development of organic integrated optoelectronic devices. [ABSTRACT FROM AUTHOR]

Organic semiconductor nanowires have inherent advantages, such as amenability to low-cost, low-temperature processing, and inherent four-level energy systems, which will significantly contribute to the organic solid-state lasers (OSSLs) and miniaturized laser devices. However, the realization of near-infrared (NIR) organic nanowire lasers is always a big challenge due to the difficultly in fabrication of organic nanowires with diameters of ≈100 nm and material issues such as low photoluminescence quantum efficiency in the red-NIR region. What is more, the achievement of wavelength-tunable OSSLs has also encountered enormous challenge. This study first demonstrates the 720 nm NIR lasing with a low lasing threshold of ≈1.4 µJ cm−2 from the organic single-crystalline nanowires, which are self-assembled from small organic molecules of ( E)-3-(4-(dimethylamino)-2-methoxyphenyl)-1-(1-hydroxynaphthalen-2-yl)prop-2-en-1-one through a facile solution-phase growth method. Notably, these individual nanowires' Fabry-Pérot cavity can alternatively provide the red-NIR lasing action at 660 or 720 nm from the 0-1 or 0-2 radiative transition channels, and the single (660 or 720 nm)/dual-wavelength (660 and 720 nm) laser action can be achieved by modulating the length of these organic nanowires due to the intrinsic self-absorption. These easily-fabricated organic nanowires are natural laser sources, which offer considerable promise for coherent light devices integrated on the optics microchip. [ABSTRACT FROM AUTHOR]

Optical interconnects exhibit superior potential in the precise regulation of photon transmission for organic photonic circuits. However, the rational design of well‐defined organic heterostructures toward active optoelectronics remains challenging. Herein, we designed organic branched heterostructures (OBHs) with accurate spatial organization for optical interconnection. Notably, the precise regulation of OBHs has been controllably achieved including the trunk morphologies and the branched microwire number. Significantly, these as‐prepared OBHs inherently exhibit the multichannel coupling outputs and the excitation position‐dependent waveguide characteristics, leading to various outcoupling signals with tunable intensity and emission colors. The optical interconnects are realized due to the occurrence of exciton conversion and photon propagation between branch and trunk at the heterojunction, benefiting the application possibilities of two‐dimensional (2D) optical barcodes. [ABSTRACT FROM AUTHOR]

Optical interconnects exhibit superior potential in the precise regulation of photon transmission for organic photonic circuits. However, the rational design of well‐defined organic heterostructures toward active optoelectronics remains challenging. Herein, we designed organic branched heterostructures (OBHs) with accurate spatial organization for optical interconnection. Notably, the precise regulation of OBHs has been controllably achieved including the trunk morphologies and the branched microwire number. Significantly, these as‐prepared OBHs inherently exhibit the multichannel coupling outputs and the excitation position‐dependent waveguide characteristics, leading to various outcoupling signals with tunable intensity and emission colors. The optical interconnects are realized due to the occurrence of exciton conversion and photon propagation between branch and trunk at the heterojunction, benefiting the application possibilities of two‐dimensional (2D) optical barcodes. [ABSTRACT FROM AUTHOR]

The solar thermoelectric (STE) generator is constituted by a high-thermopower thermocell and a NIR selective Cs 0.32 WO 3 -based photothermal membrane, which can provide a significant all-weather thermoelectric generation. This work demonstrates a novel strategy for STE devices with high solar-thermoelectric conversion, durability, adaptability, and low-cost, which provide an alternative resolution in terms of a continuous power supply of wearable electronics. [Display omitted] • A wearable solar thermoelectric generator with all-weather power output is prepared. • Selective NIR absorption of Cs 0.32 WO 3 benefits colouring and photothermal conversion. • Heat concentration of photothermal membrane promotes enhanced temperature gradient. • This work delivers a resolution of continuous power supply for wearable electronics. Harvesting heat or solar energy to directly generate affordable and sustainable electricity holds great promise toward both fundamental science and practical applications in self-powered wearable electronics. However, solar thermoelectric (STE) devices remain challenging in establishing a stable and significant temperature gradient (Δ T) across thermoelectric materials for cost-effective electricity generation. Herein, a wearable STE generator with all-weather and high-performance electricity generation was elaborately designed and synthesized sandwiched by a thermogalvanic cell and a large-area nanofiber membrane of Cs 0.32 WO 3 (CWO) nanoparticles with strong near-infrared (NIR) absorption. These prepared CWO membranes, which were prepared via an electrostatic spinning technique, present a high photothermal conversion efficiency of 42.7 % with no degradation after running for 10 cycles. Notably, a significant Δ T of 31.5 K across the thermoelectric modular was achieved for STE generation via the thermal concentration of these photothermal membranes under natural sunlight. Owing to the high thermopower of 2.87 mV K−1 for each p-n pair, STE generation demonstrates a maximum output voltage of 200 mV under natural solar irradiance during the time period of noon. This work explores a new strategy to achieve efficient heat management of STE devices for high electricity generation under all-weather conditions, which demonstrates great potential for self-powered wearable electronics. [ABSTRACT FROM AUTHOR]

• Urchin-liked nanoparticles were prepared by microwave-induced hydrolysis process. • Urchin-liked nanoparticles made up of CuO/Cu(OH) 2 substructure nanowires. • Urchin-liked nanoparticles present the porous structure with BET of 230.67 m2/g. • Maximum adsorption capacity for Cr(Ⅵ) on Cu-based nanoparticles is 357.25 mg/g. • The Cr(VI) adsorption was an endothermic and spontaneous process. The hierarchical CuO/Cu(OH) 2 urchin-like nanoparticles with branching nanowires were rationally constructed under the ultrasonic hydrolysis treatment based on the Cu-based hollow spheres by microwave treatment. Moreover, due to the novel hierarchical nanostructure with a high specific surface area (230.67 m2/g) and a porous structure (the average pore volume was 0.96 cm3/g), hierarchical CuO/Cu(OH) 2 urchin-like nanoparticles demonstrated an outstanding adsorbent properties for Cr(VI). The maximal adsorption proportion was 95.4% at 100 mg/L initial Cr(VI) concentrations, the maximum adsorption capacity at 298 K and pH 4.0 was 425.49 mg/g. [Display omitted] Hierarchical self-assembly nanomaterials with high spatial/angular precision have attracted intensive attention in the urgent research focus in industrial and environmental fields, such as the efficient removal of heavy metal ions from aqueous solution. Herein, we developed an facile microwave-induced ultrasonic hydrolysis approach for the fine synthesis of the hierarchical CuO/Cu(OH) 2 urchin-like nanoparticles, which is comprised by Cu-based substructure nanowires with an average diameter of ~5 nm. Benefiting from the high specific surface area of 230.67 m2/g, the urchin-like CuO/Cu(OH) 2 hierarchical nanoparticles demonstrated a high maximum adsorption capacity of 357.25 mg/g at pH = 6.0 and T = 298 K for Cr(VI). Furthermore, the corresponding removed approximately 95% can be achieved after the adsorption process for 30 min, suggesting the fast adsorption for Cr(VI). Thermodynamic and kinetic investigations revealed that the Cr(VI) adsorption on the urchin-like CuO/Cu(OH) 2 hierarchical nanoparticles was an endothermic and spontaneous process, which could be well fitted by the pseudo-second-order kinetic model. This approach provides new prospects for curbing heavy metal pollution in the environment based on the hierarchical self-assembly nanomaterials. [ABSTRACT FROM AUTHOR]

Mixed cation/halide perovskites have led to a significant increase in the efficiency and stability of perovskite solar cells. However, mobile ionic defects inevitably exacerbate the photoinduced phase segregation and self‐decomposition of the crystal structure. Herein, ultrathin 2D nanosheets of oxo‐functionalized graphene/dodecylamine (oxo‐G/DA) are used to solve ion migration in cesium (Cs)‐formamidinium (FA)‐methylammonium (MA) triple‐cation‐based perovskites. Based on the superconducting carbon skeleton and functional groups that provide lone pairs of electrons on it, the ultrathin 2D network structure can fit tightly on the crystals and wrap them, isolating them, and thus reducing the migration of ions within the built‐in electric field of the perovskite film. As evidence of the formation of sharp crystals with different orientation within the perovskite film, moiré fringes are observed in transmission electron microscopy. Thus, a champion device with a power conversion efficiency (PCE) of 21.1% (the efficiency distribution is 18.8 ± 1.7%) and a remarkable fill factor of 81%, with reduced hysteresis and improved long‐term stability, is reported. This work provides a simple method for the improvement of the structural stability of perovskite in solar cells. [ABSTRACT FROM AUTHOR]