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Self-powered solar-blind ultraviolet photodetectors are considered for potential applications in secure communication and space detection. However, high-quality p-type wide bandgap semiconductors are nonexistent due to the self-compensation effect, which makes the design of p-n homojunction photodetectors a challenging proposition to date. In this work, a self-powered solar-blind ultraviolet photodetector is fabricated and discussed, based on a novel heterojunction of (InxGa1−x)2O3 ternary alloy films with two different compositions, which has a flexible design and can be easily fabricated for different applications. The heterojunction consists of an amorphous (In0.23Ga0.77)2O3 on the top of a bixbyite (In0.67Ga0.33)2O3 film prepared by radio frequency magnetron sputtering. The amorphous (In0.23Ga0.77)2O3/bixbyite (In0.67Ga0.33)2O3 heterojunction photodetector exhibits a responsivity of 5.78 mA/W, a detectivity of 1.69 × 1011 cm Hz1/2 W−1, and a high solar-blind UV (248 nm)/visible light (450 nm) rejection ratio of 1.39 × 103 at zero bias, suggesting decent spectral selectivity and high performance. The responsivity and peak wavelength of this photodetector can be tuned by the film thickness of the amorphous (In0.23Ga0.77)2O3. This work provides a new design for self-powered solar-blind UV detectors based on ternary alloy heterojunctions. [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]

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]

Lycorine is an isoquinoline alkaloid in Amaryllidaceae with antitumor, antibacterial, antiviral, diuretic and cardiovascular effects. This study explored the antitumor mechanism of lycorine in vitro and in vivo by focusing on its effects on tumor cell membrane fraction and tumor cell membrane structure. The results showed that lycorine had antitumor effect on H22 tumor-bearing mice in vivo and could effectively prolong the survival time of H22 tumor-bearing mice. In vitro, lycorine inhibited the proliferation of HepG-2 cells and induced cell death significantly. Lycorine reduced the total protein content, sialic acid content and cholesterol content on the surface of tumor cell membrane, and reduced the content of some main components of tumor cell membranes. Lycorine reduced the membrane fluidity and cell membrane integrity of tumor cells. In addition, the ion channel (Na+, K+-ATPase, Ca2+, Mg2+-ATPase) activity on the surface of the tumor cell membrane decreased. This contributed to a significant antitumor effect in vitro and in vivo. [ABSTRACT FROM AUTHOR]

We report a facile method to fabricate three-dimensional (3D) porous NiO–NiCo2O4 film on Ni foam substrate through the electrostatic spray deposition (ESD) technique followed by annealing in Ar atmosphere for lithium-ion battery anodes. The structure and morphology of NiO–NiCo2O4 film were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The NiO–NiCo2O4 electrode as a binder-free anode exhibits stable cycling performance with a reversible capacity of over 1466 mAh g−1 after 100 cycles at a current density of 400 mA g−1 and good rate capability. The superior lithium storage performance of the NiO–NiCo2O4 electrode is attributed to the unique porous NiO–NiCo2O4 structures directly deposited on Ni foam, which could provide more effective void space for the volume change, and offer more contact area between the electrolyte and the electrode, and improve the electron transport. [ABSTRACT FROM AUTHOR]

ZnO nanorods (NRs) have been successfully fabricated on p-type boron-doped diamond (BDD) substrate by hydrothermal method. The current-voltage characteristics of the ZnO NRs/BDD heterojunction show a typical rectifying behavior with extremely low reverse leakage current and high rectification ratio of around 370 at bias of 3 V. Exposed to ultraviolet (UV) illumination with a wavelength of 365 nm, the time dependent photoresponse manifests high sensitivity and consistent transients with a rise time of 4.9 s and decay time of 6.4 s. Circulating on/off measurement under UV detection demonstrates the excellent stability and repeatability for as-fabricated ZnO NRs/BDD heterojunction. Furthermore, the mechanism for UV detection on the ZnO NRs/BDD heterojunction has also been discussed. [ABSTRACT FROM AUTHOR]

A series of cubic MgZnO films with a band gap of 5.0 eV (240 nm) are grown on the Si substrate by radio-frequency (rf) magnetron sputtering with various annealing temperature. Highly (111) textured single phase cubic MgZnO films with enhancement of conductivities are received through thermal annealing. The effects of annealing temperature on the structural, optical and electrical properties of cubic MgZnO films have been investigated. With increasing annealing temperature, phase separation of MgZnO films has been suppressed due to the internal strain is partially relieved by the thermal annealing. In addition, the resistivity (electron mobility, carrier concentration) decrease (increase) with an increase of annealing temperature which implies that high temperature annealing could improve the crystal quality and thereby reduce the grain boundary scattering for electron transport. Our results represent a meaningful step toward fabrication of high quality cubic MgZnO thin films use in UVC region. [ABSTRACT FROM AUTHOR]

TiO-based structure is fabricated on both sides of transparent quartz substrate via a liquid phase deposition method, with the assistance of ZnO nanorod template. The morphology, crystal structure, and photocatalytic property of the double-sided TiO nanotube arrays have been studied and the formation mechanism has been discussed. Importantly, compared to single-sided structure, the double-sided TiO nanotube arrays show remarkable enhancement of photocatalytic activity in degradation of Rhodamine B. [ABSTRACT FROM AUTHOR]

ZnO nanorod arrays (NRs) are successfully synthesized on CuO thin film by hydrothermal method. The result of scanning electron microscopy demonstrates that the ZnO NRs produce great changes on morphology after deposited on CuO thin film. The current-voltage measurement of ZnO NRs/CuO film heterostructures show an evident rectifying behavior. Furthermore, the photocatalytic activity is investigated by degradation of methyl orange dye. It is found that compared with ZnO NRs, ZnO NRs/CuO film heterostructures display a better photocatalytic activity. [ABSTRACT FROM AUTHOR]

The ZnO nanorod arrays (NRs) have been fabricated on p-type boron-doped diamond (BDD) substrate by hydrothermal method. It was demonstrated that the density and diameter of the ZnO NRs can be effectively controlled by adjusting the reactant concentration. Photocatalytic activity of the fabricated ZnO NRs/ p-BDD heterojunction was investigated for the degradation of methyl orange dye and the results indicated that diameter and density of ZnO NRs play a very important role in photocatalytic degradation. Furthermore, the ZnO NRs/ p-BDD heterostructure photocatalysts are easily recycled and reused. [ABSTRACT FROM AUTHOR]

Zinc Oxide (ZnO) nanostructures have been grown by electrochemical deposition on the indium-tin oxide (ITO) substrates. The influences and mechanism of pre-treatment of ITO on the morphology, density and size of ZnO nanostructures have been studied. Hexagonal dumbbell-like shape of ZnO bipods have been obtained because of the absence of nucleation sites on the unetched ITO substrate. An ITO etching process in dilute HCl results in the instantaneous and high density nucleation process, which was introduced to reduce the system energy and increase the growth density of ZnO nanostructures. Therefore, well-defined hexagonal and dense ZnO nanorods array are deposited on the etched ITO surface. [ABSTRACT FROM AUTHOR]

Recently, different kinds of energy band structures have been utilized to improve the photoelectric properties of zinc oxide (ZnO). In this work, ZnO nanorods were prepared by the hydrothermal method and then decorated with silver sulfide (Ag2S)/zinc sulfide (ZnS) via two-step successive ionic layer adsorption and reaction method. The photoelectric properties of nanocomposites are investigated. The results show that ZnO decorated with Ag2S/ZnS can improve the photocurrent of photodetectors from 0.34 to 0.56 A at bias of 9 V. With the immersion time increasing from 15 to 60 minutes, the photocurrent of photodetectors increases by 0.22 A. The holes in the valence band of ZnO can be transferred to the valence band of ZnS and Ag2S, which promotes the separation and suppresses the recombination of hole-electron pairs generated in ZnO. Moreover, electrons excited by ultraviolet (UV) light in Ag2S can also be injected into the conduction band of ZnO, which causes the photocurrent to increase more than the ZnO photodetector. [ABSTRACT FROM AUTHOR]

Self-Assembly Synthesis of the MoS 2 /PtCo Alloy Counter Electrodes for High-Efficiency and Stable Low-Cost Dye-Sensitized Solar Cells. The authors apologize for any inconvenience caused and state that the scientific conclusions are unaffected. Reference 1 Zeng Z., Wang D., Wang J., Jiao S., Huang Y., Zhao S., Zhang B., Ma M., Gao S., Feng X. Self-Assembly Synthesis of the MoS2/PtCo Alloy Counter Electrodes for High-Efficiency and Stable Low-Cost Dye-Sensitized Solar Cells. [Extracted from the article]

Photocatalytic water splitting into hydrogen is regarded as one of the key solutions to the deterioration of the global environment and energy. Due to the significantly reduced grain boundaries, ZnO nanorods facilitate a fast electron transfer through their smooth tunnels and are well suited as a photocatalyst. However, the photocatalytic hydrogen evolution performance of pristine ZnO nanorods is still low due to the high recombination rate of photogenerated electron-hole pairs and the less light absorption. Here, a novel structure about black ZnO nanorods (NRs)/TiO2-X mesoporous spheres (MSs) heterojunction has been prepared and the photocatalytic hydrogen evolution performance has been explored. The photocatalytic activity test results showed that ZnO NRs/TiO2-X MSs exhibited higher catalytic activity than ZnO NRs for hydrogen production. Compared to the pure ZnO NRs photoanode, the photocurrent of ZnO NRs/TiO2-X MSs heterojunction photoanode could reach 0.41 mA/cm2 in view of the expanding spectral response region and effective inhibition of e−/h+ recombination at the same condition. Using a relatively integrated experimental investigation and mechanism analysis, we scrutinized that after being treated with NaBH4, TiO2 MSs introduce oxygen vacancies expanding the photocatalytic activity of pure TiO2, and improving conductivity and charge transport capabilities through coating on ZnO NRs. More importantly, the results provide a promising approach in the NRs/MSs composite structure serving as photoanodes for photocatalytic hydrogen production. [ABSTRACT FROM AUTHOR]

In this work, MoS2 microspheres/PtCo-alloy nanoparticles (MoS2/PtCo-alloy NPs) were composited via a novel and facile process which MoS2 is functionalized by poly (N-vinyl-2-pyrrolidone) (PVP) and self-assembled with PtCo-alloy NPs. This new composite shows excellent electrocatalytic activity and great potential for dye-sensitized solar cells (DSSCs) as a counter electrode (CE) material. Benefiting from heterostructure and synergistic effects, the MoS2/PtCo-alloy NPs exhibit high electrocatalytic activity, low charge-transfer resistance and stability in the cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) test. Meanwhile, a high power-conversion efficiency (PCE) of 8.46% is achieved in DSSCs with MoS2/PtCo-alloy NP CEs, which are comparable to traditional Pt CEs (8.45%). This novel composite provides a new high-performance, stable and cheap choice for CEs in DSSCs. [ABSTRACT FROM AUTHOR]

• Scaly-like hollow SnSe nanotubes (NTs) were synthesized by a green and rapid solution method. • Light utilization efficiency is improved due to unique scaly-like hollow structure and large surface area of the SnSe NTs. • SnSe NTs infrared photodetector can realize efficient and stable IR light detection free of the external power. [Display omitted] SnSe nanotubes (NTs) have been successfully synthesized via a simple solution method. The as-synthesized tubular crystals with orthorhombic structure are composed of numerous scaly nanosheets which distributed hierarchically. The average diameter of the SnSe NTs is roughly 180 nm and length primarily concentrate in the range of 1–3 µm. It was found that Se nanowires were served as a template and as an only source of Se ion for the formation of SnSe NTs. Furthermore, a novel self-powered infrared photodetector (IRPD) established on the SnSe NTs with desirable detection performance was fabricated. Exposed to IR illumination of 830 nm, the SnSe NTs IRPD displays a maximal photocurrent density of 46.46 nA/cm2 and a rapid photoresponse, together with the rise time and decay time approach up to 0.174 s and 0.349 s, respectively. Meanwhile, it can be recognized that the SnSe NTs IRPD remain consistent and repeatable at zero voltage. Moreover, a plausible mechanism for IR detection based on the SnSe NTs IRPD are also discussed. [ABSTRACT FROM AUTHOR]

The structural and optical properties of In 0.20 Ga 0.80 N/Al x In y Ga 1− x − y N multiple quantum wells samples with varying Al content in barrier layers grown on sapphire substrates by metalorganic chemical vapor deposition have been investigated by means of high-resolution X-ray diffraction, Raman scattering measurements and temperature-dependent photoluminescence. Raman measurements verified the existence of In-rich clusters in ternary and quaternary layers. At 10 K and 300 K, the PL spectrum of each sample is dominated by a sharp emission peak arising from In 0.20 Ga 0.80 N well layers. The anomalous temperature-dependent S-shaped behaviors of emission energies have been observed, indicating the presence of localized states induced by the potential fluctuations in the quantum wells due to the inhomogeneous distribution of In-rich clusters. The degree of the localization effect and the transition temperatures between different temperature regions can be enhanced by increasing Al content in barrier layers. The improvement of the localized states emission has been observed at the lower energy side of band gap emission of quantum wells with increasing Al content. The origin of the deep localized states could be attributed to the larger quantum-confined Stark effect in the quantum wells with higher Al content. The recombination mechanism of carriers between band edge and localized states was proposed for interpreting of the emission characteristics. [ABSTRACT FROM AUTHOR]

Abstract: Our experiments show that cetyltrimethylammonium bromide (CTAB) has an obvious effect on the particle size of the precipitation of Gd(OH)3. Without CTAB, the particle size of the Gd(OH)3 precipitation is about 50 nm, whereas with CTAB, the particle size is less than 5 nm. We propose a mechanism where CTAB micelles work as a catalyst for the nucleation process and result in the precipitation of 5 nm particles. These small particles, after heat treatment at 1073 K, did not result in small Gd2O3 nanoparticles of the same size, but instead, forming crystals of 30–80 nm size in both cubic and monoclinic phases. When monitoring the photoluminescence (PL) peak at 610 nm, we found that the charge transfer state (CTS) absorption amplitude of Eu–O is reduced in the mixed structures. We speculate that the mixed structures modify the surface properties of the Gd2O3:Eu nanoparticles, leading to the reduction of Eu–O CTS absorption. [Copyright &y& Elsevier]

The (In x Ga 1-x) 2 O 3 thin films were deposited on sapphire substrates by radio frequency magnetron sputtering with increasing sputtering pressure from 0.6 Pa to 1.6 Pa. X-ray diffraction analysis indicated In composition of (In x Ga 1-x) 2 O 3 thin films maintained constant with the increase of sputtering pressure and In content and bandgaps of (In x Ga 1-x) 2 O 3 thin films were estimated to be 6% and 4.78 eV by Vegard's law, respectively. The influence of sputtering pressure on structural and optical properties was discussed in detail. Especially, the origin of different emission of (In x Ga 1-x) 2 O 3 thin films was investigated. The role of V Ga defects on the green emission centered at about 550 nm had been clarified. The energy band diagram of (In x Ga 1-x) 2 O 3 thin film was also proposed with intrinsic defect levels. • In content of (In x Ga 1-x) 2 O 3 films is 6% for all sputtering pressure condition. • Defects play an important role in luminescence. • Green luminescence is related to gallium vacancies. [ABSTRACT FROM AUTHOR]

In this work, MoS 2 microspheres/PtCo-alloy nanoparticles (MoS 2 /PtCo-alloy NPs) were composited via a novel and facile process which MoS 2 is functionalized by poly (N-vinyl-2-pyrrolidone) (PVP) and self-assembled with PtCo-alloy NPs. This new composite shows excellent electrocatalytic activity and great potential for dye-sensitized solar cells (DSSCs) as a counter electrode (CE) material. Benefiting from heterostructure and synergistic effects, the MoS 2 /PtCo-alloy NPs exhibit high electrocatalytic activity, low charge-transfer resistance and stability in the cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) test. Meanwhile, a high power-conversion efficiency (PCE) of 8.46% is achieved in DSSCs with MoS 2 /PtCo-alloy NP CEs, which are comparable to traditional Pt CEs (8.45%). This novel composite provides a new high-performance, stable and cheap choice for CEs in DSSCs.

R-Phycoerythrin (R-PE), one of the chemical constituents of red algae, could produce singlet oxygen upon excitation with the appropriate radiation and possibly be used in photodynamic therapy (PDT) for cancer. Documents reported that R-PE could inhibit cell proliferation in HepG2 and A549 cells, which was significative for cancer therapy. This is due to the fact that R-PE could kill cancer cells directly as well as by PDT. However, little is known about the cytotoxicity of R-PE to the SGC-7901 cell. In this study, it has been found that R-PE could inhibit SGC-7901 proliferation and induce cell apoptosis, which was achieved by arresting the SGC-7901 cell at S phase. CyclinA, CDK2 and CDC25A are proteins associated with the S phase, and it was found that R-PE could increase the expression of cyclin A protein and decrease the expression of CDK2 and CDC25A proteins. Thus, it was concluded that R-PE reduced the CDK2 protein activated through decreasing the CDC25A factor, which reduced the formation of Cyclin-CDK complex. The reduction of Cyclin-CDK complex made the SGC-7901 cells arrest at the S phase. Therefore, R-PE induced apoptosis by arresting the SGC-7901 cell at S phase was successful, which was achieved by the expression of the CDC25A protein, which reduced the CDK2 protein actived and the formation of Cyclin-CDK complex., Competing Interests: The authors declare no conflict of interest.

The addition of a secondary ligand, trioctylphosphine oxide, in the synthesis of cadmium selenide nanocrystals performed in a system with oleic acid as the primary ligand and octadecene as the noncoordinating solvent gives rise to the improvement of nanocrystal size distribution. This phenomenon, which is more significant in the nucleation process than in the growth process, demonstrates that the existence of trioctylphosphine oxide allows for superior nucleation control and permits the facile and reproducible production of extremely small CdSe nanocrystals with narrow size distribution. A systematic study of the nanocrystal formation processes shows that the well-established colloidal nanocrystal growth mechanism, in which nucleation is followed by focusing of size distribution and ended with defocusing of size distribution, cannot be applied to our reactions. Instead, we observed an exceptional type of growth mechanism in which, after nucleation, clear defocusing instead of focusing follows; then slight focusing occurs.