Improvement of Ga_(2)O_(3)vertical Schottky barrier diode by constructing NiO/Ga_(2)O_(3)heterojunction

The high critical electric field strength of Ga_(2)O_(3)enables higher operating voltages and reduced switching losses in power electronic devices.Suitable Schottky metals and epitaxial films are essential for further enhancing device performance.In this work,the fabrication of vertical Ga_(2)O_(3)barrier diodes with three different barrier metals was carried out on an n--Ga_(2)O_(3)homogeneous epitaxial film deposited on an n+-β-Ga_(2)O_(3)substrate by metal-organic chemical vapor deposition,excluding the use of edge terminals.The ideal factor,barrier height,specific on-resistance,and breakdown voltage characteristics of all devices were investigated at room temperature.In addition,the vertical Ga_(2)O_(3)barrier diodes achieve a higher breakdown volt-age and exhibit a reverse leakage as low as 4.82×10^(-8)A/cm^(2)by constructing a NiO/Ga_(2)O_(3)heterojunction.Therefore,Ga_(2)O_(3)power detailed investigations into Schottky barrier metal and NiO/Ga_(2)O_(3)heterojunction of Ga_(2)O_(3)homogeneous epitaxial films are of great research potential in high-efficiency,high-power,and high-reliability applications.

A drug-loaded composite coating to improve osteogenic and antibacterial properties of Zn-1Mg porous scaffolds as biodegradable bone implants

Zinc(Zn)alloy porous scaffolds produced by additive manufacturing own customizable structures and biodegradable functions,having a great application potential for repairing bone defect.In this work,a hydroxyapatite(HA)/polydopamine(PDA)composite coating was constructed on the surface of Zn-1Mg porous scaffolds fabricated by laser powder bed fusion,and was loaded with a bioactive factor BMP2 and an antibacterial drug vancomycin.The microstructure,degradation behavior,biocompatibility,antibacterial performance and osteogenic activities were systematically investigated.Compared with as-built Zn-1Mg scaffolds,the rapid increase of Zn2+,which resulted to the deteriorated cell viability and osteogenic differentiation,was inhibited due to the physical barrier of the composite coating.In vitro cellular and bacterial assay indicated that the loaded BMP2 and vancomycin considerably enhanced the cytocompatibility and antibacterial performance.Significantly improved osteogenic and antibacterial functions were also observed according to in vivo implantation in the lateral femoral condyle of rats.The design,influence and mechanism of the composite coating were discussed accordingly.It was concluded that the additively manufactured Zn-1Mg porous scaffolds together with the composite coating could modulate biodegradable performance and contribute to effective promotion of bone recovery and antibacterial function.