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In this Letter, we report a high-performance NiO/β-Ga2O3 pn heterojunction diode with an optimized interface by annealing. The electrical characteristics of the pn diode without annealing (PND) and with annealing (APND) are studied systematically. The APND device has a lower specific on-resistance of 4.1 mΩ cm2, compared to that of the PND, 5.4 mΩ cm2. Moreover, for the APND, a high breakdown voltage of 1630 V with lower leakage current is achieved, which is 730 V higher than that of the PND. The enhanced electrical performance of the APND leads to a record high power figure of merit of 0.65 GW/cm2 in Ga2O3-based pn diodes, which is among the best reported results in Ga2O3 power devices. In addition, the interface trap density of the diode decreases from 1.04 × 1012 to 1.33 × 1011 eV−1 cm−2 after annealing, contributing to much lower hysteresis. Simultaneously, the ideality factor n for the APND is steady at elevated temperatures due to the stable interface. The results of C − V characteristics reveal the bulk defects inside the nickel oxide film grown by sputtering, which are calculated by high- and low-frequency capacitance methods. X-ray photoelectron spectroscopy of NiO illustrates the reasons for the changes in the concentration of holes and defects in the film before and after annealing. This work paves the way for further improving the performance of Ga2O3 diode via interface engineering. [ABSTRACT FROM AUTHOR]

Byline: Jiong. Dai, Shanquan. Li, Xiaoxiong. Li, Wenhao. Xiong, Yongming. Qiu Background : Intraventricular hemorrhage (IVH) is an independent risk factor for both morbidity and mortality in patients with intracerebral [...]

In this letter, trench-gate metal–oxide–semiconductor field-effect transistors on (010) $\beta $ -Ga2O3 epitaxial layer are fabricated. Enhancement mode is achieved by the gate-recess process, through thoroughly depleting the $\beta $ -Ga2O3 channel to get a positive threshold voltage. For the first time, by using a dynamic parameter test system, the Ga2O3 MOSFET with 2- $\mu \text{m}$ gate length is characterized to present short switching time, including turn-on time ($\textit {t}_{ \mathrm{\scriptscriptstyle ON}}$) of 28.6 ns and turn-off time ($\textit {t}_{ \mathrm{\scriptscriptstyle OFF}}$) of 94.0 ns. In addition, OFF-state interelectrode parasitic capacitances, including input capacitance ($\textit {C}_{\text {iss}}$) of 37 pF/mm, output capacitance ($\textit {C}_{\text {oss}}$) of 42 pF/mm, and reverse transfer capacitance ($\textit {C}_{\text {rss}}$) of 14 pF/mm are also obtained, which can account for the high switching speed. The static and dynamic switching properties of the trench-gate device show the potential of $\beta $ -Ga2O3 MOSFET for the high-speed switching applications. [ABSTRACT FROM AUTHOR]

Submerged plants are an important part of aquatic ecosystems, and the restoration of submerged plants is a key step in the reconstruction of aquatic ecosystems. However, little is known about the role of modified sediments in helping submerged plants recover under low light. In this study, we set up four sediment types and two light intensities to explore the effects of modified sediments on the growth of Vallisneria natans under two low light conditions. The results showed that the independent and interactive effects of light intensity and sediment type significantly affected the biomass, morphology, photosynthetic pigment content and antioxidant enzyme activity of V. natans . At 5% and 20% natural light intensity, the sediment modified with 40% peat soil had a larger root biomass and the highest leaf and root C/N ratio, the sediment modified with 40% vermiculite had a longer root length and more ramets. At 5% natural light intensity, the sediments modified with fly ash had shorter root length and smaller leaf biomass. The sediments modified with fly ash had the greatest chlorophyll content at 20% natural light intensity. It can be concluded that the addition of 40% peat soil or 40% vermiculite in sediment is conducive to the growth of V. natans under low light conditions. Our study indicates the positive effects of the modified sediment on the growth of V. natans under low light conditions, and our study will provide a reference for the restoration of submerged plants in aquatic ecosystems., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Xiong, Ma, Xie and Zeng.)