A series of MgxZn1−xO thin films has been prepared by metalorganic chemical vapor deposition and metal-semiconductor-metal structured ultraviolet photodetectors are fabricated from these films. The cutoff wavelengths of the photodetectors can cover the whole solar-blind spectrum range (220–280 nm) by varying Mg content in the MgxZn1−xO thin films. As a representative, the photodetector fabricated from Mg0.52Zn0.48O shows an ultraviolet/visible rejection ratio of about four orders of magnitude, and the dark current is 15 pA at 10 V bias. These results demonstrate that high-performance photodetectors operating in the whole solar-blind spectrum range can be realized in MgxZn1−xO films.

Surface plasmons, a unique property of metal nanoparticles, have been widely applied to enhance the performance of optical and electrical devices. In this study, a high quality zinc oxide (ZnO) thin film was grown on a quartz substrate by a radio frequency magnetron sputtering technique, and a metal-semiconductor-metal structured ultraviolet detector was prepared on the ZnO film. The responsivity of the photodetector was enhanced from 0.836 to 1.306 A/W by sputtering metal (Pt) nanoparticles on the surface of the device. In addition, the absorption of the ZnO thin film was enhanced partly in the ultraviolet band. It is revealed that Pt nanoparticles play a key role in enhancing the performance of the photodetectors, where surface plasma resonance occurs.

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Zn0.8Mg0.2O metal–semiconductor–metal ultraviolet photodiodes were fabricated on quartz by radio frequency magnetron sputtering. Dark current, spectral responsivity and pulse response experiments were carried out for the device. The photodetectors showed a peak responsivity at 330 nm. The ultraviolet-visible rejection ratio (R330 nm/R400 nm) was more than four orders of magnitude at 3 V bias. The photodetector showed fast photoresponse with a rise time of 10 ns and a fall time of 170 ns. In addition, the thermally limited detectivity was calculated to be 3.1 × 1011 cm Hz1/2 W−1 at 330 nm.

The ZnO flexible ultraviolet photodetectors (UV PDs) with poly(ethylene terephthalate) (PET) substrate are manufactured successfully at room temperature, and the effect of strain on PDs performance are studied. When subjected to 0.2 tensile stress, the responsivity of PDs is increased by 20% and sensitivity is increased by 770%. This is due to the influence of piezo‐phototronic effect on the transport behavior of photogenerated carriers at the interface of ZnO/Au Schottky junction. The polarization charge generated by the piezoelectric element breaks the original thermodynamic equilibrium. As a consequence, the charge at the interface is being redistributed, and the Schottky barrier height (SBH) and depletion layer width change, thus regulating the interface characteristics. This effect has value for the optimization and regulation of the UV PDs performance. Furthermore, current study proves that the piezo‐phototronic effect not only exists in ZnO nanomaterials, but also has a significant piezo‐phototronic effect on high‐quality thin film ZnO materials. In addition, this study also provides an extension field for flexible UV PDs based on piezo‐phototronic effect of semiconductor materials.

Planar wheel-type D6h M©B6H6(-/0/+) (M = Mn, Fe and Co for anion, neutral and cation, respectively.) clusters with a planar hexacoordinate transition-metal at the center of the boron ring were designed and investigated by density functional theory. These planar clusters are chemically stable as a result of their large binding energy, vertical ionization potential, and vertical electron affinity. The detailed natural population and molecular orbital analyses suggest that not only does the M atom donate electrons to the boron ring for participation in the π-delocalized bonding, but also the boron ring donates electrons back to the M atom for the formation of the σ-delocalized bonding, which leads to a strong aromaticity and unconventional charge distribution, i.e., the M atom is negatively charged, while the boron ring is positively charged. This study may open a new area in coordination chemistry for planar hexacoordinate transition metals and we expect further experimental exploration of their synthesis and potential applications.

Flexible visible-light photodetectors were fabricated by dispersing a large number of Sb2Se3 nanowires onto the Au interdigitated electrodes on PET substrates, which showed fast response speed and excellent flexibility.