Search

The β -Ga2O3 ultraviolet (UV) detectors work in the solar-blind (UV) band due to the ultra-wide bandgap of β -Ga2O3. In this paper, a solar-blind ultraviolet detector based on an ordered nanoporous β -Ga2O3 (ONP- β -Ga2O3) film is proposed and implemented. The local enhancement effect of the ordered nanopores on light is simulated by finite-difference time-domain method, and the period and diameter of the nanopores are optimized. Graphene is transferred on the ONP- β -Ga2O3 film and prepared as interdigital electrodes of the solar-blind ultraviolet detectors. The optimal detector has a photo-to-dark current ratio of about 4.64 × 103 at a 5 V bias, a peak response of 2.43 A Wâˆ'1 at 254 nm, and a UV/visible rejection ratio of about 1081. We demonstrate that the ordered nanoporous structure can localize optical field effectively, which results in enhancement of light absorption as well as improvement of key detector parameters. [ABSTRACT FROM AUTHOR]

High performance β–Ga2O3 trench Schottky barrier diodes (SBDs) were demonstrated with the employment of a novel etching technique called self-reactive etching (SRE). Owing to the high-quality surface without any etched damages and impurities, the β–Ga2O3 trench SBDs showed temperature-dependent electrical characteristics. Negligible charge trapping and hysteresis indicated the high quality of the interface between the Al2O3 dielectric and the β–Ga2O3 layer. Only a few changes of the capacitance–voltage curves measured at different temperatures have been shown, suggesting an excellent thermal stability. A high current density of 1228 A cm−2 and ION/IOFF ratio of 1010 indicated the excellent rectifying characteristics. An ideality factor of 1.23 and barrier height of 1.58 eV confirmed the surface repair and reconstruction from the SRE process. These results indicate that SRE can be beneficial for the β–Ga2O3 etching and the future development of β–Ga2O3 power electronics. [ABSTRACT FROM AUTHOR]

Lateral epitaxial growth in vertical β-Ga2O3 nanowires was studied on sapphire substrates via metal organic chemical vapor deposition by controlling growth temperature and O2 flow rate. The lateral epitaxial growth rate of β-Ga2O3 rise up with increasing growth temperature and decreasing O2 flow rate, which are related to reaction kinetics and parasitic reaction, respectively. In addition, a growth model is proposed to explain the morphology of nanowires when growth condition changes. These results can provide important guidance on addressing slow coalescence rate of β-Ga2O3 nuclear islands on heterogeneous substrates and open new doors to β-Ga2O3 optoelectronic and electronic devices on cost-effective foreign substrates. [ABSTRACT FROM AUTHOR]

Controllable deposition of Ga droplets on a GaN template is discussed in detail in the present work. It is found that the Ga droplet density shows apparent nonlinear dependence on the flux of triethylgallium under certain annealing conditions. A simplified model based on the weakening of cluster mobility is proposed to explain the phenomenon. In addition, based on the different mobility of Ga on different substrates, a SiO2 mask with ordered nanopore array is designed and optimized for controllable catalyst deposition. By further optimizing the deposition and annealing process, a higher filling rate of nanopores is obtained, and ordered β-Ga2O3 nanowire arrays perpendicular to substrates are then achieved. The controllable uniform vertical nanowire array would further promote optimization of nanowire growth and device fabrication. [ABSTRACT FROM AUTHOR]