We present a practical vacuum pressure sensor based on the Schottky junction using graphene anchored on a vertically aligned zinc oxide nanorod (ZnO-NR). The constructed heterosystem of the Schottky junction showed characteristic rectifying behavior with a Schottky barrier height of 0.64 eV. The current–voltage (I–V) features of the Schottky junction were measured under various pressures between 1.0 × 103 and 1.0 × 10− 3 mbar. The maximum current of 38.17 mA for the Schottky junction was measured at – 4 V under 1.0 × 10− 3 mbar. The high current responses are larger than those of the previously reported vacuum pressure sensors based on ZnO nanobelt film, ZnO nanowires, and vertically aligned ZnO nanorod devices. The pressure-sensitive current increases with the vacuum pressure and reaches maximum sensitivity (78.76%) at 1.0 × 10− 3 mbar. The sensitivity and repeatability of the Schottky junction were studied by the current–time (I–T) behavior under variation of vacuum pressure. The sensing mechanism is debated from the surface charge transfer doping effect by oxygen chemisorption. The results suggest that this simple graphene/ZnO-NR Schottky junction device may have potential in the fabrication of vacuum pressure sensor with high sensitivity.

In this work, we developed silver nanowires and a silicon based Schottky junction and demonstrated ultrafast broadband photosensing behavior. The current device had a response speed that was ultrafast, with a rising time of 36 μs and a falling time of 382 μs, and it had a high level of repeatability across a broad spectrum of wavelengths (λ = 365 to 940 nm). Furthermore, it exhibited excellent responsivity of 60 mA/W and a significant detectivity of 3.5 × 1012 Jones at a λ = 940 nm with an intensity of 0.2 mW cm2 under zero bias operating voltage, which reflects a boost of 50%, by using the AC PV effect. This excellent broadband performance was caused by the photon-induced alternative photocurrent effect, which changed the way the optoelectronics work. This innovative approach will open a second door to the potential design of a broadband ultrafast device for use in cutting-edge optoelectronics.

The electrical properties of Au/n-type Ge Schottky contacts with different contact areas were investigated using current-voltage (I-V) measurements. Analyses of the reverse bias current characteristics showed that the Poole-Frenkel effect became strong with decreasing contact area. The contribution of the perimeter current density to the total current density was found to increase with increasing reverse bias voltage. Fitting of the forward bias I-V characteristics by considering various transport models revealed that the tunneling current is dominant in the low forward bias region. The contributions of both the thermionic emission (TE) and the generation-recombination (GR) currents to the total current were similar regardless of the contact area, indicating that these currents mainly flow through the bulk region. In contrast, the contribution of the tunneling current to the total current increased with decreasing contact area. The largest E00 value (related to tunneling probability) for the smallest contact area was associated with higher tunneling effect.