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All‐inorganic metal halide perovskites are competitive candidate as next‐generation flexible photodetectors (PDs) materials due to the remarkable photoelectric properties, enhanced heat stability, and mechanical flexibility. However, constructing low‐cost flexible perovskites PDs with high photodetection performance, good operation stability and mechanical robustness, and manufacturing corresponding flexible PDs array have been a challenge. Herein, the PbCl2 and Zinc(II) Dibenzyldithiocarbamate (Zn(DBDTC)2) are employed to modify bottom and top interface of CsPbIBr2 perovskite layer, respectively, to passivate surface trap state, enhance hydrophobicity and resist phase segregation, and improve interface contact. Consequently, the self‐powered champion PDs with low‐cost Bi2Te3 electrode reach a responsivity of 0.38 A W−1 and a maximum detectivity of 3.44 × 1013 Jones at 570 nm, and maintain the outstanding long‐term and operational stability without additional encapsulation. Meanwhile, the HTL‐free flexible PDs based on low‐temperature CsPbIBr2 perovskite layer exhibit impressive photodetection performance and mechanical robustness in bending test. More importantly, the flexible PDs array (5 × 5 pixels) and corresponding imaging system are fabricated with uniform and clear imaging results under flatting and bending state. This research is of great significance for the application of stable and high‐performance inorganic perovskites PDs and flexible array imaging systems. [ABSTRACT FROM AUTHOR]

Encrypted optical communication is a critical technology in numerous fields, including remote sensing, environmental monitoring, and homeland defense. As a core of wireless interconnect systems, the conventional photodetectors generally receive optical signals from a single direction and fail to distinguish between various wavebands, severely undermining the potential for data transfer and protection. Herein, a Bi2O3 layer‐integrated waveband‐discriminated perovskite photodetector is presented. By rational design of energy band and device architecture, the novel photodetector is self‐powered, double‐sided responsive, and recognizable to the short or long‐wave UV, as well as visible optical signals. Without external bias, the device exhibits a high performance with peak responsivities of 42.1 and 72.3 mA W−1 in frontal and reverse incidence, respectively. Benefiting from these advantages, the photodetector is applicable to optical communication and encryption. In reverse incidence, reversible message delivery is achieved through the conversion and decoding of illumination patterns and binary digits. For a further step, the encrypted processing is fulfilled in frontal incidence. By virtue of the eight irradiation combinations, a secret key containing ten‐bit commands will generate over a billion encryption methods. This work realizes a new mode of communication and encryption that entirely relies on optical signals, offering new insights into wireless communication. [ABSTRACT FROM AUTHOR]

Statistics provided by GLOBOCAN list gastric cancer as the sixth most common, with a mortality ranking of third highest for the year 2020. In China, a herb called Rabdosia rubescens (Hemsl.) H.Hara, has been used by local residents for the treatment of digestive tract cancer for hundreds of years. Oridonin, the main ingredient of the herb, has a curative effect for gastric cancer, but the mechanism has not been previously clarified. This study mainly aimed to investigate the role of TNF‐alpha/Androgen receptor/TGF‐beta signalling pathway axis in mediating the proliferation inhibition of oridonin on gastric cancer SGC‐7901 cells. MTT assay, cell morphology observation assay and fluorescence assay were adopted to study the efficacy of oridonin on cell proliferation. The network pharmacology was used to predict the pathway axis regulated by oridonin. Western blot assay was adopted to verify the TNF‐α/Androgen receptor/TGF‐β signalling pathway axis regulation on gastric cancer by oridonin. The results showed Oridonin could inhibit the proliferation of gastric cancer cells, change cell morphology and cause cell nuclear fragmentation. A total of 11signaling pathways were annotated by the network pharmacology, among them, Tumour necrosis factor alpha (TNF‐α) signalling pathway, androgen receptor (AR) signalling pathway and transforming growth factor (TGF‐β) signalling pathway account for the largest proportion. Oridonin can regulate the protein expression of the three signalling pathways, which is consistent with the results predicted by network pharmacology. These findings indicated that oridonin can inhibit the proliferation of gastric cancer SGC‐7901 cells by regulating the TNF‐α /AR /TGF‐β signalling pathway axis. [ABSTRACT FROM AUTHOR]

Films with excellent flexibility and mechanical stability are important for flexible and wearable devices. However, most films reported are prepared on substrates, and the synthesis of freestanding flexible films remains a challenge. Herein, a freestanding Bi2S3 nanofibrous membrane (NFM) is successfully prepared via a one‐step hydrothermal method, which is self‐assembled from ultralong Bi2S3 nanowires (NWs) over a length of millimeter‐scale crisscrossing each other. Significantly, the Bi2S3 NFM can be bent or clipped into an arbitrarily desired form. Based on the freestanding Bi2S3 NFM, an IR photodetector is fabricated, depicting a robust responsivity of 2.23 (2.06) µA W−1 under 850 (940) nm illumination. The Bi2S3 NFM photodetector exhibits a relatively fast response time (47.1 ms), which is attributed to high‐speed carrier transport efficiency in the NWs network. Under the bending states, the device still exhibits excellent detection performance, maintaining more than 86% of the initial photocurrent even after 1000 bending‐flattening times. The robust photoresponse of the Bi2S3 NFM photodetector after 2 months of storage in air and after 1 week in the bending state illustrates its excellent air stability and flexible detection ability. Besides, the photodetector can clearly identify the target image, indicating widespread potential applications in flexible and wearable fields. [ABSTRACT FROM AUTHOR]

Integrating a third component into the binary system is considered to be one of the most effective strategies to further enhance the power conversion efficiency (PCE) in organic solar cells (OSCs). Here, a novel perylene diimide (PDI) derivative featuring 3D structure, TPA‐4PDI, with tetraphenyladamantane central core is developed as a guest electron acceptor to be incorporated into the PM6:Y6 binary system. The champion PCE of ternary OSC is recorded to be 18.29% by adding 7.5 wt.% of TPA‐4PDI in the ternary blend, which photovoltaic performance is enhanced with synergistically increased open‐circuit voltage (Voc) of 0.849 V, short‐circuit current density (Jsc) of 27.55 mA cm−2, and fill factor (FF) of 78.21%. TPA‐4PDI exhibits a complementary absorption band with PM6 and Y6 while its lowest unoccupied molecular orbital (LUMO) energy level falls between the two host materials. The addition of TPA‐4PDI can effectively suppress the recombination behavior, inhibit the excessive aggregation of Y6 and improve the morphology of PM6:Y6 blend. All these effects function synergistically and then lead to the enhancement of Voc,Jsc, and FF in ternary OSCs. This study suggests that developing PDI derivatives as the third component is an effective method to further improve the performance of ternary OSCs. [ABSTRACT FROM AUTHOR]

The conventional forward‐structure perovskite devices typically employ organic small molecule and noble metal as the hole transport layer (HTL) and electrode, respectively, which results in poor thermal stability and high costs. To address this issue, a HTL‐free CH3NH3PbBr3 photodetector with the topological insulator bismuth telluride (Bi2Te3) electrode is developed. The device exhibits apparent sensitivity to ultraviolet/visible waveband with a peak responsivity of 97.5 mA W−1, switching ratio exceeding 104, and the detectivity is up to 1012 Jones without external bias. These figures‐of‐merit are distinguished among the reported CH3NH3PbBr3‐based devices. Impressively, this device presents a light power‐modulated near‐infrared detection thanks to the contribution of topological insulator Bi2Te3, and the underlying mechanism is elaborated in‐depth. Moreover, the novel device improves significantly in short and long‐time thermal stability. Benefiting from these distinguished properties, the photodetector is imaging‐capable and a 50 × 50 pixels' pattern with satisfactory resolution has been achieved. This work highlights the application of topological insulators on the HTL‐free perovskite photodetector, offering new insights for the future commercialization of perovskite devices. [ABSTRACT FROM AUTHOR]

In inverted perovskite solar cells (PSCs), n‐doping fullerene electron transport layers (ETLs) have been found to prepare high efficiency devices due to their excellent performance in electrochemistry, film formability, and surface passivation. Herein, two cathode interface layers (CILs) 2PDI‐FN and 2PDIT‐FN are prepared with dimethylamino functional groups and PDI units. The addition of thiophene makes the 2PDIT‐FN conjugated framework coplanar and enhances the effect of dimethylamino functional groups, which give 2PDIT‐FN with higher electrical conductivity, electron mobility, self‐doping property, and film formability. Moreover, dopant N‐DMBI can further enhance these advantages of 2PDIT‐FN. Consequently, a peak power conversion efficiency (PCE) of 20.44% is achieved with 2PDIT‐FN(+) as CIL, much higher than 18.77% of 2PDI‐FN(+) one, which is only 17.71% and 19.06% for 2PDI‐FN and 2PDIT‐FN‐based one, respectively. The significant improvement in device efficiency is due to reduced defect density, lower dark current, larger recombination resistance, and better surface morphology, which improves charge transport and collection at the PC61BM/Ag interface. In a word, this molecular design approach with molecular configuration regulation and functional groups provides a direction for the preparation of cathode interface materials to achieve high performance of PSCs. [ABSTRACT FROM AUTHOR]

Nanostructured semiconductor materials synthesized through solution processes have received a substantial body of attention owing to their cost‐effectiveness, manufacturing ease, and environmental friendliness. Here, a simple solution approach is used to synthesize Bi2Se3/Se nanorods (NRs) heterojunction by covering Se NRs with a uniform Bi2Se3 shell. The morphology, composition, and structure of the samples are characterized and the growth mechanism is also analyzed. Furthermore, the photodetector based on the Bi2Se3/Se NRs is fabricated. The as‐prepared Bi2Se3/Se NRs photodetector exhibits an outstanding broadband photoresponse from UV (365 nm) to IR (850 nm) with good repeatability and self‐powered ability. Upon light illumination, Bi2Se3/Se NRs photodetector shows maximum photocurrent of 190 µA (UV light), 194 µA (blue light), 145 µA (green light), 38 µA (red light), 4 µA (IR light) as well as a rapid response time around 0.1 s approximately. Moreover, a possible detection mechanism of Bi2Se3/Se NRs photodetector is also discussed. [ABSTRACT FROM AUTHOR]

ZnO/ZnS/CuS net‐like nanosheet (NS) heterojunction array was fabricated via a simple solution method at a low temperature. Morphology and structure of ZnO/ZnS/CuS NS were characterized by scanning electron microscope (SEM) and Transmission electron microscope (TEM). With tiny particles attaching on the rough surface, the thin ZnO/ZnS/CuS NS grew vertically and arranged regularly on Al substrate, providing large effective illumination area and massive active sites. Elemental composition and valence state were confirmed with energy dispersive X‐ray spectrometry and X‐ray photoelectron spectroscopy (XPS), respectively. The UV–vis absorbance spectra indicated that the absorption range of ZnO NS was expanded to the visible region effectively, and the original absorption intensity in the ultraviolet region was also improved after being coated with ZnS and CuS. Photocatalytic activity tests of ZnO, ZnO/ZnS, and ZnO/ZnS/CuS NS were carried out with methyl orange as a simulated pollutant, in which ZnO/ZnS/CuS heterojunction showed great enhancement when making comparison with pure ZnO and ZnO/ZnS NS. After five reuse cycles, photocatalytic performance could still be maintained well, indicating the good catalytic stability. Finally, a probable photocatalytic mechanism was also discussed. [ABSTRACT FROM AUTHOR]

Hydrangea‐like ZnO nanospheres were fabricated on Al substrates via a facile hydrothermal method with only one step. Scanning electron microscopy, energy‐dispersive spectroscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, and photoluminescence were used to investigate their morphology, component, structure, and optical properties. The hierarchical nanospheres are fabricated by 2D nanosheets with the shape of 3D sphere. By adjusting the reaction time, the formation process was monitored. The photocatalytic activity of ZnO nanospheres was also investigated for their dye degradation, and they exhibit good photocatalytic ability to congo red, with the degradation rate of 98.4%. Besides, they have universal catalysis effect on methyl orange. [ABSTRACT FROM AUTHOR]

CuO nanoplates (NPs) have been prepared on ZnO nanorods (NRs) to form heterostructure by a simple photodeposition method at room temperature. The morphology, composition, and structure of the as‐prepared CuO NPs/ZnO NRs heterostructure were analyzed by SEM, TEM, XPS, and XRD. UV/Vis absorption spectrum indicates that the CuO NPs/ZnO NRs heterostructure exhibits a strong absorption in both the UV and visible light region. Photocurrent response results and the photoluminescence spectrum confirm that the CuO NPs/ZnO NRs heterostructure could promote the separation of photogenerated carriers. The photocatalytic ability of the as‐prepared samples was evaluated by degrading methyl orange. Moreover, the possible growth and photocatalytic mechanisms of the CuO NPs/ZnO NRs heterostructure were discussed. [ABSTRACT FROM AUTHOR]

A simple, low‐cost synthetic approach was developed for fabricating a TiO2 layer on the surface of CdS‐sensitized ZnO nanorods by a liquid‐phase deposition method. In the ZnO/CdS/TiO2 composite structure, CdS quantum dots are grown on ZnO nanorods and the resulting CdS/ZnO nanorods are uniformly coated with a TiO2 layer. UV/Vis absorption spectroscopy showed that CdS could provide better light‐harvesting ability, and the photocatalytic activity was significantly improved by CdS compared with that of ZnO nanorods alone. Recycling experiments on ZnO/CdS showed continuous attenuation of photocatalytic performance, whereas the TiO2 protective layer maintains superior photocatalytic performance of the photocatalyst and strongly inhibits the photocorrosion of CdS. In addition, a possible photocatalytic mechanism of the ZnO/CdS/TiO2 composite is proposed. [ABSTRACT FROM AUTHOR]

Phosphorus-doped ZnO nanorods were successfully prepared by hydrothermal method using ammonium dihydrogen phosphate as the dopant source. The effects of different Zn sources, zinc nitrate concentration, reaction duration, ammonium dihydrogen phosphate concentration, and annealing temperature on the morphologies and phosphorus content of ZnO nanorods were investigated. The doping mechanism of phosphorus-doped ZnO nanorods has been discussed. Detailed photoluminescence studies of phosphorus-doped ZnO revealed characteristic phosphorus acceptor-related peaks: neutral acceptor-bound exciton emission at 3.347 eV, and donor-to-acceptor pair emission at 3.232 eV, free-electron to neutral-acceptor emission at 3.312 eV. This means that stable acceptor levels with a binding energy of about 126 meV were formed by phosphorus doping. [ABSTRACT FROM AUTHOR]

Versatile ZnO nanostructures have been fabricated by a two-step hydrothermal method. Controllable growth of ZnO is feasible by using different kinds of zinc sources. It is revealed by scanning electron microscopy that ZnO nanorods with average diameter 155 nm were synthesized by using Zn(CH3COO)2 as the zinc source. As for the situation when Zn(NO3)2 was used, taper-like ZnO nanostructure with large aspect ratio was formed. In particular, two-dimensional ZnO nanosheets can be fabricated when ZnCl2 was introduced and the distinctive X-ray diffraction spectrum indicates that the anisotropic growth of ZnO along its <0001> direction was hindered, which was caused by the attraction of Cl− ions onto the ZnO polar face instead of growth units. Consequently, the anisotropic growth of ZnO along this direction was hindered, while the other two samples were vertically aligned against the substrates, which can be deduced from their sharp and strong ZnO (002) diffractions. Additionally, their optical properties including the absorptions of ultraviolet light and the corresponding optical bandgaps were also measured by an ultraviolet-visible spectrometer, which changed with the structural transformations. All these properties make them feasible for applications in the fields of both solar cells and biosensors. [ABSTRACT FROM AUTHOR]

Two novel benzo[1,2‐b:4,5‐b′ ]difuran (BDF)‐based wide‐bandgap polymers, PBDFT‐FBz and PBDFF‐FBz, featuring a difluorobenzotriazole (FBz) acceptor unit, are designed and synthesized. The first attempt through main‐chain engineering to alter thiophene units to furan units in the main chain of PBDFT‐FBz, and further side‐chain engineering eliminate the 2‐ethylthiophenyl side chains of PBDFT‐FBz by 2‐ethylfuryl side chains to generate the "all‐furan" polymer PBDFF‐FBz. By taking the benefit of the oxygen atom in furan, both PBDFT‐FBz and PBDFF‐FBz exhibit lower HOMO energy levels and enhanced polymer chain interactions compared to their benzo[1,2‐b:4,5‐b′ ]dithiophene (BDT)‐based counterparts. As a result, while applying both polymers in non‐fullerene polymer solar cells with non‐fullerene acceptor m‐ITIC, both devices exhibit highly promising photovoltaic performance. The power conversion efficiency (PCE) in the PBDFT‐FBz device reaches 7.57% with increased open circuit voltage (Voc) and fill factor (FF) compared to the PCE of 5.98% in its BDT counterpart (J52). A further increased PCE is obtained (8.79%) in the PBDFF‐FBz:m‐ITIC device, which shows ≈47% enhancement in device performance compared to that of J52. The large increase in photovoltaic performance is attributed to the lower‐lying HOMO energy levels and better chain interactions in these BDF‐based polymers. [ABSTRACT FROM AUTHOR]