GaN high-electron-mobility transistor (HEMT)-based gated-anode diodes (GADs) for 5.8 GHz high-power rectenna application are proposed. Using HEMTs with a recessed gate structure, the GAD significantly improves maximum anode forward current and reverse breakdown voltage simultaneously. Rectifying performance simulated with SPICE model shows that the GAD is a promising device for high-power rectenna at 5.8 GHz.

AlN substrate offers various advantages, such as high breakdown voltage and high-temperature operation. Herein, a N-polar AlGaN/AlN-heterostructured field-effect transistor (FET) with static FET characteristics is successfully fabricated. However, the drain current density, I_DS, remains significantly small. This study aims to improve I_DS by doping Si in the topmost AlGaN channel layer under various conditions.

The performance potentials and limits for GaN current aperture vertical electron transistors with conventional, doped, and natural polarization (PSJ) superjunction drift layers at 1.2–10 kV BV ratings are quantitively compared by extracting their static and dynamic performance parameters using technology computer-aided design simulation. PSJ offers the best performance with at least 22% and 80% at 1.2 and 10 kV respectively.

Fabrication techniques for high-reflectivity (HR) and antireflection (AR) dielectric multilayer mirrors for AlGaN-based ultraviolet-B (UV-B) laser diodes are developed. By mounting those mirrors on both edges of the device, the improvement of device performance is confirmed, such as increased light output and slope efficiency.

AlGaN/GaN lateral transistors fabricated with >10 μm thick buffers on 200 mm diameter-engineered substrates are demonstrated. The engineered substrates result in minimal residual stress in the GaN buffer while the fabricated transistors display both electrical and thermal performance competitive with other substrate technologies such as Si. A pathway for large-scale production of high-yield GaN devices is presented.

Piezoelectric AlScN single-crystal films deposited by metal–organic chemical vapor deposition are used for the first time in the fabrication of bulk acoustic wave filters. The effects of growth conditions are discussed and novel structures are produced to manage internal stresses and preserve planar surface morphology.

Herein, N-polar Al_0.1Ga_0.9 N/Al_0.9Ga_0.1 N/AlN field-effect transistor (FET) is fabricated using metal–organic vapor-phase epitaxy, and the static FET operation is confirmed to exhibit an n-channel and pinch-off.

Herein, the power performance of an AlGaN/GaN high-electron-mobility transistor (HEMT) with AlN buffer on SiC substrate, grown by high-temperature metal–organic chemical vapor deposition, is presented. The fabricated devices are examined and show positive characteristics, such as low slump ratio and breakdown voltage. The potential of using an AlN buffer HEMT is demonstrated by the results for use in high-power radio-frequency devices of the future.

AlGaN/GaN high electron mobility transistors (HEMTs) on engineered substrates are grown with different GaN/AlGaN buffer layer thickness and evaluated via atomic force microscopy, high-resolution X-ray diffraction, Raman spectroscopy, and steady-state thermoreflectance. Fabricated HEMTs are evaluated via DC and pulsed electrical techniques and thermoreflectance imaging. It is reported that these HEMTs exhibit high GaN quality, low stress, low current collapse, and low thermal resistance.

Cross-sectional transmission electron microscope (TEM) images of the recessed-gate structure on a thin AlGaN/GaN channel metal oxide semiconductor heterojunction field-effect transistor fabricated by selective area regrowth. The thin AlGaN/GaN channel with an AlGaN back barrier and the regrown AlGaN/GaN high electron mobility transistor structure provides low on-resistance and normally off operation.

Laser diodes with different InGaN quantum well thicknesses up to 25 nm are analyzed. Efficient screening of the piezoelectric field and excited-state operation are reported. The time-dependent behavior below threshold gives insights about the quantum well tilt and the wave function overlap. A sharp intensity increase and wavelength shift are observed at the end of the pulse.

An extended PGaN gate structure that can reduce the peak electric field is proposed and successfully adopted on a Schottky PGaN enhancement-mode GaN high-electron-mobility transistor platform. The device features a saturation current of 256 mA mm⁻¹, a threshold voltage of +1.8 V, and an ON-resistance of 19.781 Ω mm.

AlGaN templates are fabricated using the spontaneous nucleation and AlN nanopillar methods, and ultraviolet-B (UV-B) laser diodes (LDs) with the same structure are fabricated on them. Herein, three and six times higher values for S_d and P_peak are confirmed, respectively, using templates fabricated using the AlN nanopillar method. The method of AlN nanopillars is realized by high-performance UV-B LDs.

The reliability of ultraviolet-C (UV-C) light-emitting diodes (LEDs) is crucial for next-generation disinfection systems. Herein, the electrical, optical, and spectral properties of UV-C LEDs with an emission peak of 275 nm during their lifetime are analyzed. The analysis allows to determine the optimal balance between performance, reliability, and costs in a solid-state disinfection system.

The high-performance ferroelectric charge storage gate (FEG) gallium nitride high-electron-mobility transistors (HEMT) has gradually gained attention due to the concept being a useful tool to realize E-mode operations, which has been a focused topic in recent years for their potential applications. This article attempts to review the latest progress in this technology, including alternative improvements and device characteristics.

By introducing the hole-type patterned sapphire substrate (HPSS) with a properly designed pattern configuration as a substrate for AlN growth, threading dislocation density (TDD) is significantly lowered from 1.48 × 10⁹ to 4.38 × 10⁸ cm⁻². The TDs on the mesa zones generated at AlN/sapphire interface can be effectively suppressed by bending toward coalescence zone during the subsequent lateral overgrowth.

I–V characteristics investigation in the function of temperature shows barrier height inhomogeneities for vertical GaN Schottky diodes. These inhomogeneities are a common and crucial issue for power device application. Their potential origin (strain, doping variation, electrically active defects) is studied using Raman spectroscopy and deep-level transient spectroscopy.

GaInN heterostructure sensors are optimized primarily for hydrogen sulfide sensing. Thin GaN cap layer, thick GaInN quantum well (QW), and low-doping concentration with a gold functionalization layer are found to be better for sensitivity in the 10–100 parts per billion (ppb) range. Ammonia gas is also detected in the 5–10 ppm range.

Codoping of gallium nitride for improved acceptor ionization has long been theorized; here we show significantly improved p-type doping of GaN with donor coimplantation for formation of low-activation energy complexes. Transmission line measurements, photoluminescence, and p-type hall exhibit vast improvement with additional oxygen donors compared to silicon having significant implications for device topologies requiring colocated dopants or utilizing n-polar material.