In this work, a novel gallium oxide (Ga2O3) vertical FinFET with integrated Schottky barrier diode (SBD-FinFET), which achieves low conduction losses, is proposed. In the reverse conduction state, the integrated SBD can provide additional low-resistance path to conduct reverse current, hence achieving low reverse conduction loss. In the switching state, the SBD-FinFET can also reduce gate–drain capacitance and gate charge, thus featuring fast switching speed and low switching losses. Furthermore, in the other states, the integrated SBD of the SBD-FinFET is in the OFF state, which does not significantly affect the device characteristics. The well-calibrated simulation results show that when compared with the state-of-the-art FinFET with integrated Fin channel and ohmic contact diode (FOD-FinFET), the SBD-FinFET can reduce reverse conduction loss, turn-on loss, and turn-off loss by 25%, 19%, and 22%, respectively, while other characteristics retain almost unchanged.

Single-phase multicolor phosphors with a cryolite structure were obtained via energy transfer from Tb³⁺ to Eu³⁺.

Improvements in phase stability and dielectric characteristics can broaden the applications of zirconia in ceramics. Herein, a series of Y₂O₃-stabilized zirconia (YSZ) ceramics are synthesized using solid-state sintering, followed by an investigation into their phase evolution, grain size, dielectric constant, and breaking field. As the Y₂O₃ content increases from 0 wt% to 4 wt%, the as-grown YSZ ceramics undergo a distinct phase transformation, transitioning from monoclinic to monoclinic + tetragonal and further to monoclinic + tetragonal + cubic, before finally returning to monoclinic + cubic. Significant changes occur in the internal microstructure and grain size of the ceramics as the phase composition alters, resulting in a reduction in grain size from 3.17 μm to 0.27 μm. Moreover, their dielectric constants exhibit an increasing trend as the Y₂O₃ content increases, rising from 3.92 to 13.2. Importantly, the dielectric breakdown field of these YSZ ceramics shows a similar variation to the phase evolution, ranging from 0.11 to 0.15 MV/cm. This study sheds light on the phase evolution and dielectric properties of YSZ ceramics, offering an efficient strategy for enhancing their dielectric performances.

We report the phase shift of two types of photodetectors for a variation of bias voltage and optical power. One type is PIN-PD, and the other is a modified uni-traveling carrier photodetector (MUTC-PD). In PIN-PD, the phase change shows a photocurrent-dependent variation of about 15 degrees at 3 GHz. It exhibits good stability over a wide bandwidth as the bias voltage changes. By comparison, the phase shift of the MUTC-PD is more sensitive to the bias voltage and the photocurrent. The continuous tunable range of phase shift in MUTC-PD reaches 50 degrees at 10 GHz. It is demonstrated that the adjustable phase shift mainly results from the transit time and the impedance dynamic effects in response to the optical power and bias voltage.

Solar-blind ultraviolet photodetectors are utilized in various military and civilian fields, encompassing missile tracking, high-voltage detection, and fire warning systems. Ga ₂ O ₃ emerges as the prime candidate for such photodetectors owing to its elevated bandgap, remarkable thermal stability, and facile fabrication process. The metal-semiconductor-metal (MSM) structure garners attention for its swift response time and straightforward preparation, thus becoming a focal point among diverse photodetector architectures. Nevertheless, the metal surface impedes optical absorption, thereby diminishing the quantum efficiency of the photodetector. In this work, we introduce a nanograting onto the Ga ₂ O ₃ surface, which results in a 747-fold increase in responsivity in the solar-blind ultraviolet (SBUV) region compared to a normal MSM grating-free structure. Metal gratings can induce surface plasmon polaritons, thereby augmenting the optical absorption of the photodetector and stimulating hot electrons to increase photocurrent. However, the broadband response caused by the introduction of metal gratings is a common problem. By optimizing the doping concentration of the Ga ₂ O ₃ absorption layer, adjusting the incident light intensity, and reverse voltage, the problem of broadband response has been solved. The responsivity of the device in the non-SBUV region is suppressed 24-fold. This methodology holds promise as a reliable approach for fabricating high-performance SBUV photodetectors.

We report the measurements and characterizations of optoelectronic harmonic mixing in a modified uni-traveling carrier photodetector (MUTC-PD). A systematic study of the bias voltage-dependent properties of the output power under different input optical power levels has been made and the proper operating conditions for different mixing modes have been investigated. In addition to the fundamental mixing, the higher-order harmonic mixing and RF subharmonic mixing products were obtained. The harmonic mixing mechanism is mainly attributed to the nonlinearity of the dependence of the output power on the bias voltage. Flat intermediate responses over a wide RF signal frequency range were measured for the fundamental mixing and the high-order RF subharmonic mixing. The feasible harmonic optoelectronic mixing in MUTC-PD shows great application potential in the wireless multichannel communication system.