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The properties of ultraviolet (UV) photodetector fabricated on TiO2/diamond film were investigated. Single crystal diamond layer was grown on high-pressure-high-temperature Ib-type diamond substrate by microwave plasma chemical vapor deposition method, upon which TiO2 film was prepared directly using radio frequency magnetron sputtering technique in Ar and O2 mixing atmosphere. Tungsten was used as electrode material to fabricate metal-semiconductor-metal UV photodetector. The dark current is measured to be 1.12 pA at 30 V. The photo response of the device displays an obvious selectivity between UV and visible light, and the UV-to-visible rejection ratio can reach 2 orders of magnitude. Compared with that directly on diamond film, photodetector on TiO2/diamond film shows higher responsivity.

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In this research, Ginkgo biloba L. seeds (GBS) were freeze-dried, infrared-dried, hotair dried, and pulsed-vacuum dried. A detailed analysis of their drying kinetics (drying curve, drying rate curve, effective moisture diffusivity, mathematical modeling), shrinkage and energy efficiency (specific moisture extraction, specific energy consumption), and physicochemical properties (soluble solids, total sugar, reducing sugar, ascorbic acid, phenolics, and tannins) were performed. Results showed drying methods had various effects on different indexes and were confirmed by principal component analysis. The drying process occurred in the falling-rate period. The effective moisture diffusivity values amongst various drying methods ranged from 3.5 × 10 −8 to 7.6 × 10 −8 m 2 /s, which were within the normally expected range for food materials. The exponential model best fitted the experimental results for drying with coefficient of determination (R 2 ) > .981 and root mean square error, sum of square error, and reduced chi-square closer to zero than the parabolic and inverselogarithmic (Log3p1) models. The freeze-dried GBS had the highest nutritional (statistically the same with the fresh GBS) and lower shrinkage; nevertheless, it had the lowest moisture extraction rate and the highest energy consumption. Hot-air dried GBS had the highest shrinkage and lowest nutritional retention. Infrared-dried GBS was superior with the highest non-tannic phenolic, proanthocyanidins content, effective moisture diffusivity, drying rates, and energy efficiency. The current findings indicate that infrared drying is a promising drying technology for GBS and has the potential to be applied on a commercial scale. Practical applicationGinkgo seeds (GBS) are utilized as functional food across Asia. In China, ginkgo trees' extensive cultivation has surpassed market requirements, as GBS production could reach 60,000 tons per year. Therefore, there is an urgent need to find new opportunities to take advantage of the availability and usage of GBS regardless of the season and overcome the situation that GBS usage only remains at incipient phases of home-cooked recipes. Drying is a common approach to preserve foods'.Nonetheless, there are some drawbacks to conventional drying method, such as low energy efficiency, lengthy process periods, and a decline in quality attributes.

A monolithic diamond photodetector with microlenses is fabricated by etching microlens arrays (MLAs) on single crystal diamond surface and patterning tungsten electrode strips on the edge of these arrays. Firstly, compact MLAs are etched on half of diamond sample surface by thermal reflow method. Secondly, via magnetron sputtering technique, two sets of interdigitated tungsten electrodes are patterned on the sample surface, one set is on the edge of MLAs, the other set is on the planar area. The optoelectronic performances of photodetectors have been investigated and indicated that the photocurrent of microlens photodetector increases by 74.8 percent at 10 V under 220 nm UV light illumination by comparing with that in planar case. Simulations of photodetectors' electrical and optical properties have been carried out, illustrating an improvement of charge collection ability and light absorption efficiency in microlens case. Furthermore, the present device structure can be extended to other semiconductor photodetectors.

We numerically calculate the wave function of two-dimensional electron gas (2DEG) for use in 2DEG transport theory and study the electron transport in ZnMgO/ZnO heterostructures. For strongly confined 2DEG, the temperature dependence of the electron mobility is satisfactorily explained using 2DEG transport theory. The interface roughness and ionized impurity scatterings play important roles in the electron transport at low and moderate temperatures. At room temperatures polar optical phonon scattering is the most important scattering mechanism. For heterostructures having two parallel conduction paths in the 2DEG at the ZnMgO/ZnO interface and in the ZnO thick layer, the electron transport is contributed by the two paths. We calculate the mobility for the respective conduction paths, and then combine the two mobility components to fit the experimental data. The theoretical calculations are in good agreement with the experimental data.

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