There is an emerging need for high-sensitivity solar-blind deep ultraviolet (DUV) photodetectors with an ultra-fast response speed. Although nanoscale devices based on Ga 2 O 3 nanostructures have been developed, their practical applications are greatly limited by their slow response speed as well as low specific detectivity. Here, the successful fabrication of two-/three-dimensional (2D/3D) graphene (Gr)/PtSe 2 /β-Ga 2 O 3 Schottky junction devices for high-sensitivity solar-blind DUV photodetectors is demonstrated. Benefitting from the high-quality 2D/3D Schottky junction, the vertically stacked structure, and the superior-quality transparent graphene electrode for effective carrier collection, the photodetector is highly sensitive to DUV light illumination and achieves a high responsivity of 76.2 mA/W, a large on/off current ratio of ~ 10 5 , along with an ultra-high ultraviolet (UV)/visible rejection ratio of 1.8 × 10 4 . More importantly, it has an ultra-fast response time of 12 s and a remarkable specific detectivity of ~ 10 13 Jones. Finally, an excellent DUV imaging capability has been identified based on the Gr/PtSe 2 /β-Ga 2 O 3 Schottky junction photodetector, demonstrating its great potential application in DUV imaging systems.

In this paper a convenient and universal strategy for preparing nanoring arrays of different compositions based on a colloidal‐crystal‐template strategy is reported. Large‐area arrays of polystyrene, magnetite, Au, Si, magnetite nanoparticle/polystyrene and Au/polystyrene double‐layer composite nanorings are prepared. Many kinds of nanoring structures, including Fe3O4 nanoparticle/polystyrene and Au/polystyrene double‐layer nanorings, can be released from the substrates, resulting in free‐standing composite nanorings, which might be used as self‐assembly building blocks and ultrasensitive bio‐ and chemical sensors.

A high-performance self-powered photodetector based on a MoS2/GaAs heterojunction was demonstrated, which demonstrated a high responsivity, specific detectivity, fast response speeds, as well as high polarization sensitivity.

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A self-driven photodetector based on WS2/GaAs type-II Zener heterojunction is fabricated, which shows a broadband response spectrum from 200 to 1550 nm beyond the limitation of the bandgaps with a high responsivity and specific detectivity.

In this work, position effects of an alkylthio side chain were investigated by designing and synthesizing two copolymers based on a phenylsubstituted benzo[1,2-b:4,5-b′]dithiophene (BDTP) and difluorobenzotriazole (FTAZ). The polymer based on the meta-position-alkylthiolated BDTP, named m-PBDTPS−FTAZ, showed a relatively broader bandgap (2.00 vs 1.96 eV) and lower highest occupied molecular orbital (HOMO) energy level (−5.40 vs −5.32 eV) than its para-positioned structural isomeric analogue polymer (named p-PBDTPS−FTAZ), that is, m-and p-PBDTPS−FTAZ with the side chain structured as ethylhexyl-in the phenyl unit and hexyldecyl-in the FTAZ moiety. When blended with ITIC, m-PBDTPS−FTAZ showed a comparable crystallinity but more uniform morphology compared to that of p-PBDTPS−FTAZ. A high power conversion efficiency of 13.16% was achieved for m-PBDTPS−FTAZ:ITIC devices with a high open circuit voltage (V OC ) of 0.95 V, which is higher than that of p-PBDTPS−FTAZ:ITIC devices (10.86%) with a V OC of 0.89 V. Therefore, m-BDTPS could be an effective donor unit to construct high-efficiency polymers due to its effectively decreased HOMO energy level of polymers while still maintaining good molecular stacking.

High-performance self-powered ultraviolet (UV) photodetector based on a WS2/GaN heterojunction was demonstrated, which exhibits excellent UV photoresponse properties. Significantly, this photodetector has exhibited excellent UV imaging capability.

This paper investigates the influence of the combination of the scalability parameters in scalable video coding (SVC) schemes on the subjective visual quality. We aim at providing guidelines for an adaptation strategy of SVC that can select the optimal scalability options for resource-constrained networks. Extensive subjective tests are conducted by using two different scalable video codecs and high definition contents. The results are analyzed with respect to five dimensions, namely, codec, content, spatial resolution, temporal resolution, and frame quality.