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Articles you may be interested inPerformance improvement of GaN-based ultraviolet metal-semiconductor-metal photodetectors using chlorination surface treatment J. Vac. Sci. Technol. B 30, 031211 (2012); 10.1116/1.4711215 Effect of asymmetric Schottky barrier on GaN-based metal-semiconductor-metal ultraviolet detector Response of ultra-low dislocation density GaN photodetectors in the near-and vacuum-ultraviolet J. Appl. Phys. 95, 8275 (2004); 10.1063/1.1748855 GaN metal-semiconductor-metal ultraviolet photodetector with IrO 2 Schottky contact Appl. Phys. Lett. 81, 4655 (2002); 10.1063/1.1524035High-speed, low-noise metal-semiconductor-metal ultraviolet photodetectors based on GaN

Hydrothermal conversion of sugars exceeded 98.0% with lactic acid yield reaching 67.1% over a Sn-Beta zeolite catalyst prepared via a green synthesis.

An enhanced spectral response was realized in an AlGaN-based solar-blind ultraviolet (SB-UV) detector using aluminum (Al) nanoparticles (NPs) of 20-60 nm. The peak responsivity of the detector (about 288 nm) with 60 nm Al NPs is more than two times greater than that of a detector without Al NPs under a 5-V bias, reaching 0.288 A/W. To confirm the enhancement mechanism of the Al NPs, extinction spectra were simulated using time-domain and frequency-domain finite-element methods. The calculation results show that the dipole surface plasmon resonance wavelength of the Al NPs is localized near the peak responsivity position of AlGaN-based SB-UV detectors. Thus, the improvement in the detectors can be ascribed to the localized surface plasmon resonance effect of the Al NPs. The localized electric field enhancement and related scattering effect result in the generation of more electron-hole pairs and thus a higher responsivity. In addition, the dark current of AlGaN-based SB-UV detectors does not increase after the deposition of Al nanoparticles. The results presented here is promising for applications of AlGaN-based SB-UV detectors.

An asymmetric Schottky barrier metal-semiconductor-metal (MSM) ultraviolet (UV) detector with Ni/GaN/Au structure was designed and the effect of the asymmetric Schottky barrier on the detector response was investigated. This detector had response at 0 V bias and increased responsivity when a positive bias was applied to the Ni/GaN contact; however, the internal gain disappeared when a negative bias was applied to this point. This contrasts with a symmetric Ni/GaN/Ni Schottky barrier MSM UV detector which had no internal gain under positive/negative bias and almost no response at 0 V bias. The improved performance of the asymmetric Schottky barrier detector was because of the lower work function of Au causing reduction of Schottky barrier and hence enhancing a hole-accumulating and trapping process, which resulted in internal gain.

A high yield of HMF is directly obtained from aquatic microalgae over a commercial acidic zeolite under mild conditions. Experimental results reveal that proteins and lipids in microalgal cells benefit the HMF stability in water.

High spectral response of self-driven GaN-based ultraviolet detectors with interdigitated finger geometries were realized using interdigitated Schottky and near-ohmic contacts. Ni/GaN/Cr, Ni/GaN/Ag, and Ni/GaN/Ti/Al detectors were designed with zero bias responsivities proportional to the Schottky barrier difference between the interdigitated contacts of 0.037 A/W, 0.083 A/W, and 0.104 A/W, respectively. Voltage-dependent photocurrent was studied, showing high gain under forward bias. Differences between the electron and hole mobility model and the hole trapping model were considered to be the main photocurrent gain mechanism. These detectors operate in photoconductive mode with large photocurrent gain and depletion mode with high speed, and can extend GaN-based metal-semiconductor-metal detector applications.