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The excellent conductive surface electronic states of topological insulators make them suitable candidates for the next generation optoelectronic devices. Moreover, their unique semiconducting properties are favorable for building heterojunctions with other semiconductors. Here, we fabricated a low cost and broadband self-powered photodetector based on Sb

Graphene-structure WSe

The excellent conductive surface electronic states of topological insulators make them suitable candidates for the next generation optoelectronic devices. Moreover, their unique semiconducting properties are favorable for building heterojunctions with other semiconductors. Here, we fabricated a low cost and broadband self-powered photodetector based on Sb2Te3 and Si. The photolithography and thermal evaporation technique were combined to fabricate a series of asymmetric planar Sb2Te3 electrodes on the surface of an n-type silicon substrate. An obvious asymmetrical current voltage curve occurred under dark conditions, which is ascribed to the asymmetry of each electrode. During the photodetection test, self-powered photodetection was obtained upon 940 nm light irradiation. Moreover, the photodetector exhibited fast and broadband photodetection from 365 nm to 940 nm with a response time less than 40 ms.

Graphene-structure WSe2 nano-films (NFMs) were prepared by magnetron sputtering and vacuum selenization. The as synthesized WSe2 NFMs were characterized using various techniques such as SEM, XRD and EDS. Our work provides a simple and effective method to prepare WSe2 NFMs. We have observed the high photo responsivity of WSe2 NFMs up to 10 A W-1, which is 40% higher than the previously reported data. Our photoelectrochemical tests demonstrate that WSe2 NFMs have excellent photoelectric properties, indicating that NFMs have a wide application potentialsin solar cells and optoelectronic devices.

Graphene-ZnO (GZO) nanocomposites were synthesized by a modified solvothermal method, and characterized by transmission electron microscopy, x-ray diffraction, Raman spectra, and UV-vis absorption spectra. The controllable nonlinear optical (NLO) properties of as-prepared GZO nanocomposites were tested by an open-aperture Z-scan method with 1030 nm fs laser pulses; the tested results showed that there were five-photon absorption (5PA) at 46.8 GW cm-2, 3PA at 28.1 GW cm-2, 2PA at 18.7 GW cm-2, and a vital change from saturable absorption (SA) to reverse SA (RSA) with the increase of incident intensity. This was the first time that 5PA was found in GZO nanocomposites at such a low intensity, 46.8 GW cm-2. The tunable NLO property from SA to RSA and controllable multi-photon absorption provided a facile approach for their applications in optical, optoelectronic devices, and information storage.

ISOBAM-104 protected Rh/Ag bimetallic nanoparticles (NPs) with average diameter less than 3.0 nm were synthesized by a co-reduction method. Ultraviolet–visible spectroscopy, transmission electron microscopy (TEM), high-resolution TEM and x-ray photoelectron spectroscopy (XPS) were employed to characterize the structure, particle size, and electronic structure of the prepared bimetallic NPs. The catalytic activities of prepared bimetallic NPs for hydrogen generation from hydrolysis of a basic KBH4 solution were evaluated in detail. The results indicated that as-prepared Rh/Ag bimetallic NPs showed a higher catalytic activity than corresponding monometallic NPs. Among all the monometallic NPs and bimetallic NPs, Rh80Ag20 bimetallic NPs exhibited the highest catalytic activity with a value of 6010 mol-H2h−1mol-catalyst−1 at pH = 12 and 303 K. The high catalytic activities of Rh/Ag bimetallic NPs could be attributed to presence of negatively charged Rh atoms and positively charged Ag atoms, which is supported by the results of XPS and density functional theory calculation. Based on the kinetic study, the apparent activation energy for the hydrolysis reaction of the basic KBH4 solution catalyzed by Rh80Ag20 bimetallic NPs was about 47.0 ± 3.9 kJ mol−1.