To further improve the performance of all-inkjet-printing ZnO UV photodetector and maintain the advantages of inkjet printing technology, the inkjet printing Ag nanoparticles (NPs) were deposited on the inkjet printing ZnO UV photodetector for the first time. The inkjet printing Ag NPs can passivate the surface defects of ZnO and work as surface plasmons from the characterization of photoluminescence (PL), X-ray photoelectron spectroscopy (XPS), and finite difference time domain method (FDTD) simulation. The normalized detectivity (D *) of the Ag NP-modified detector reaches to 1.45 × 10 10 Jones at 0.715 mW incident light power, which is higher than that of 5.72 × 10 9 Jones of the bare ZnO photodetector. The power-law relationship between the photocurrent and the incident light power of the Ag NP-modified ZnO detector is I pc ∝ P 2.34 , which means the photocurrent is highly sensitive to the change of incident light power.

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This study investigates the effects of thermal annealing on Al-doped MgxZn1−xO (AMZO) films. AMZO films were deposited by a radio-frequency magnetron sputtering system using a 4 in. ZnO/MgO/Al2O3 (76/19/5 wt. %) target. This study measures and reports the Hall results, x-ray diffraction (XRD), transmittance, and x-ray photoelectron spectroscopy (XPS) data. XRD results show that the ZnO (002) and MgO2 (002) wurtzite peaks in addition to the (111)-cubic peak disappeared after 1000 °C annealing. This indicates the coexistence of two phases in the as-grown AMZO films rebuilt after higher thermal treatment. The absorption edges of these as-grown AMZO films shifted toward the short wavelength of 323 nm under 80% transmittance, implying that band gaps can be tuned by changing the Mg content of the AMZO layer. The XPS spectra of AMZO films were also used to analyze the composition of the as-grown and annealed AMZO films.

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In this study, a 50-nm Al0.05Ga0.95N back barrier (BB) layer was used in an AlGaN/GaN high-electron-mobility transistor between the two-dimensional electron gas channel and Fe-doped/C-doped buffer layers. This BB layer can reduce the channel layer. The BB layer is affected by doped carriers in the buffer layer and the conduction energy band between the channel and the buffer layers. The Ion/Ioff ratio of the BB device was 4.66 × 105, and the ratio for the device without BB was 1.91 × 103. Lower leakage currents were obtained in the BB device because of the higher conduction energy band. The 0.25-μm gate length device with the BB exhibited a high current gain cutoff frequency of 24.4 GHz, and power gain cutoff frequency of 73 GHz.

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