Search

With the increasing demand for modern high‐voltage electronic devices in electric vehicles and renewable‐energy systems, power semiconductor devices with high breakdown fields are becoming essential. β‐Gallium oxide (Ga2O3), which has a theoretical breakdown field of 8 MV cm−1, is being studied as a next‐generation power‐switch material. However, realizing a breakdown field close to this theoretical value remains challenging. In this study, an aerosol deposition‐manufactured Ga2O3 film boasting an extremely high breakdown field, achieved through thickness optimization, heat treatment, and a unique nozzle‐tilting method, is developed. This study explores the effect of oxygen vacancies on the dielectric constant, breakdown field, and microstructure of Ga2O3 films. Through these methods, Ga2O3 films with a denser (98.88%) and uniform surface, made less affected by oxygen vacancies through nozzle tilting and post‐annealing at 800 °C, are produced, resulting in appropriate dielectric constants (9.3 at 10 kHz), low leakage currents (5.8 × 10−11 A cm−2 at 20 kV cm−1), and a very high breakdown field of 5.5 MV cm−1. The results of this study suggest that aerosol‐deposited Ga2O3 layers have great potential to enable power switches with reliable switching.

Abstract The ability of controlling the phase of light at the subwavelength scale can be a game-changer due to its extraordinally wide angle-range in the wavefront shaping. By combining two conventional material and configuration, liquid crystal and distributed Bragg reflectors, we are getting close to this ultimate goal.

Holographic displays that are both compact and produce realistic holograms without eyestrain are still difficult to realize. Here the authors implement a steering-backlight unit and a holographic video processor to produce a realistic holographic display in a slim panel.

Controlling the phase of light with a high efficiency and precision is essential for applications in imaging, tunable devices, and optical systems. Spatial light modulators (SLMs) based on liquid crystals (LCs) have been regarded as one of the best choices for the generation of phase profiles for the steering of light. The upper glass substrate has an unpatterned electrode for a common electrode, while the lower glass substrate has one-dimensional micro-patterned electrodes for controlling the single pixel level by the applied voltages. By applying different voltages to each electrode to create a sawtooth-shaped phase profile, the collimated input beam is deflected to the desired angle. To maximize the diffraction efficiency (DE) values, an advanced simulation method has been developed to find the optimized phase profile through the analysis of LC director distributions. The resulting diffraction patterns are investigated both computationally and experimentally, with a good agreement between the results obtained. Finally, the beam deflector (BD) system with an advanced driving algorithm has a high 1st order DE, about 60%, 37%, and 7.5% at 1°, 2.5°, and a maximum steering angle of 7.5°, respectively. The LC director distributions in relation to various diffraction angles are simulated and an experimental success in realizing enhanced DE for the beam steering device is presented.