TiN/GaN Schottky barrier diodes with different anode diameters are fabricated to investigate the temperature sensing mechanism. All the circular diodes present good stability over a temperature range of 25 °C-200 °C. In the fully turn-on region, the sensitivity increases with the increasing diameter. Furthermore, the highest sensitivity of 1.22 mV/K is obtained for a 300-μm-diameter device at current of 20 mA, taking into account the series resistance. In the subthreshold region, the forward current (ID) density determines the sensor sensitivity, in which a larger current density corresponds to a lower sensitivity. In addition, the strong dependence of the leakage current on the temperature indicates that the linearity of ln (Ir) versus temperature can be also used for sensor applications.

FTO–BiVO₄–W–WO₃ photoanode is fabricated in this study.

This article presents a finger-type gallium nitride (GaN) Schottky barrier diode (SBD)-based microwave rectifier with medium-power capacity and wide power bandwidth. A complete solution including SBD design and fabrication, model extraction, circuit optimization, and demonstration is proposed. The finger-type anode and critical thickness epitaxial layer techniques are adopted to reduce the GaN SBD resistance to 1.9 Ω (0.011 m · cm ² ) and achieve nearly constant junction capacitance over a wide range of voltages (17-25V). Revised equivalent models including the effects of large pads, critical thickness epitaxial layer, and finger-type layout are proposed to describe the new features of the SBD. A 2.45-GHz microwave rectifier based on the GaN SBD is designed and measured, having a maximum power and an efficiency of 1.91 W and 78.5%, respectively. The high-efficiency power range (≥70% and ≥75%) is significantly extended to 14 and 10.8 dB. Finally, a wireless clinical examination prototype constructed by a rectifier, antennas, biomedical sensors, and a signal processer is proposed for demonstration. The resulting wireless electrocardiogram shown in computer is clear and stable.