Gallium nitride (GaN) ultraviolet metal-semiconductor-metal photodetectors (PDs) grown on Si substrates were demonstrated. The dark current of PDs fabricated on Si substrates was substantially smaller in magnitude compared to identical devices prepared on sapphire substrates. With an incident wavelength of $359\mathrm{nm}$ , the maximum responsivities of the $n^{-}\text{‐}\mathrm{Ga}\mathrm{N}$ MSM photodetectors with TiW and $\mathrm{Ni}∕\mathrm{Au}$ contact electrodes were 0.187 and $0.0792\mathrm{A}∕\mathrm{W}$ , corresponding to quantum efficiencies of 64.7% and 27.4%, respectively. For a given bandwidth of $1\mathrm{kHz}$ and a given bias of $5\mathrm{V}$ , the corresponding noise equivalent powers of our $n^{-}\text{‐}\mathrm{Ga}\mathrm{N}$ MSM photodetectors with TiW and $\mathrm{Ni}∕\mathrm{Au}$ electrodes were $1.525\times {10}^{-12}$ and $5.119\times {10}^{-12}\mathrm{W}$ , respectively. Consequently, the values of detectivity $\left(D^{*}\right)$ determined for devices with TiW and $\mathrm{Ni}∕\mathrm{Au}$ electrodes were then calculated to be $1.313\times {10}^{12}$ and $3.914\times {10}^{11}\mathrm{cm}{\mathrm{Hz}}^{0.5}{\mathrm{W}}^{-1}$ , respectively.

In this study, Atomic Layer Deposition (ALD) equipment was used to deposit Al₂O₃ film on a p-type silicon wafer, trimethylaluminum (TMA) and H₂O were used as precursor materials, and then the post-annealing process was conducted under atmospheric pressure. The Al₂O₃ films annealed at different temperatures between 200–500 °C were compared to ascertain the effect of passivation films and to confirm the changes in film structure and thickness before and after annealing through TEM images. Furthermore, the negative fixed charge and interface defect density were analyzed using the C-V measurement method. Photo-induced carrier generation was used to measure the effective minority carrier lifetime, the implied open-circuit voltage, and the effective surface recombination velocity of the film. The carrier lifetime was found to be the longest (2181.7 μs) for Al₂O₃/Si post-annealed at 400 °C. Finally, with the use of VHF (40.68 MHz) plasma-enhanced chemical vapor deposition (PECVD) equipment, a silicon nitride (SiN_x) film was plated as an anti-reflection layer over the front side of the wafer and as a capping layer on the back to realize a passivated emitter and rear contact (PERC) solar cell with optimal efficiency up to 21.54%.

The bipolar resistive switching properties of Pt/ZnO/Pt multilayer film structure were investigated in this study. The M-H curves corresponding to the Pt/ZnO/Pt bipolar resistive switching device maintained at initial, high resistance, and low resistance states were individually obtained; all of which were ferromagnetic in nature. The strength of saturation magnetization of the device separately set at low resistance state, and the initial state was found to be strongest and weakest, respectively. Photoluminescence and X-ray photoelectron results indicate the presence of oxygen vacancies in the ZnO thin film. This resistive switching behavior accompanied with ferromagnetism could be attributed to the intrinsic defects. The results clearly demonstrate that the ferromagnetic switching capability of Pt/ZnO/Pt device is critically dependent on the bias voltage administered, which potentially allows this device to have magneto-electrical device applications.