GaN-based semiconductors attract much attention owing to the theoretically high Curie temperature of GaN-based diluted magnetic semiconductors and novel spin-orbit coupling(SOC) properties due to the strong polarization electric field. To overcome the conductance mismatch issue in a two-dimensional electron gas (2DEG) system, we take an ultrathin AlN layer at the hetero-interface as a barrier to form high-quality 2DEG in the triangular quantum well and a tunneling barrier for the spin injection. As for spin relaxation, owing to the canceled spin–orbit coupling (SOC), the spin relaxation time as long as 311 ps in InGaN/GaN multiple quantum wells is obtained at room temperature, being much longer than that in bulk GaN. Further, spin-polarized carrier transfer and spin relaxation processes in 2DEG of the InGaN/GaN QW were investigated by photon-energy dependent TRKR measurements.
InGaN alloys have gained considerable interest over the past due to their tunable band gap extending the operation wavelengths of optoelectronic devices to green–red and IR regions. However, the realization of high In-content InGaN materials is still limited by their material properties. Despite encouraging achievements in InGaN based devices, it is difficult to achieve high quality InGaN with high indium composition. Up to now, there are only few reports about high indium content InGaN films, in particular with indium content > 50%.
Successfully grown In-rich InGaN layers with 300 nm thickness and nominally [In] = 70% deposited on GaN template by MBE were comprehensively investigated by highly spatially-resolved cathodoluminescence. The surface morphology has been investigated by atomic force microscope (AFM) and scanning electron microscopy (SEM) and shows grain-like features. The lateral as well as the vertical luminescence distribution yields a detailed insight in the [In] homogeneity. The thick InGaN films, free of droplets, have a quite homogenous emission at 1.035 eV (~1200 nm) laterally with full-width at half maximum of only 68 meV. Determined from the emission peak, the indium composition is about 75%, which is slightly higher than the nominally intended indium composition. The evolution in growth direction will be presented.
AlGaN-based ultraviolet (UV) light sources have recently attracted much research interest due to their potential candidate to replace excimer and mercury lamps. However, their output power is limited by the inefficient p-type doping at high Al composition AlGaN. In this talk, we will report on the electron-beam-pumped UV light sources, where multiple ultrathinGaN wells are used to enhance the internal quantum efficiency and to reach deep UV range such as 230 nm. And UV light source with wavelength varing from 285-232 nm with corresponded output power of 23-160 mW have been achieved under pulse mode.
Conference Committee Involvement (8)
Gallium Nitride Materials and Devices XIX
29 January 2024 | San Francisco, California, United States
Gallium Nitride Materials and Devices XVIII
30 January 2023 | San Francisco, California, United States
Gallium Nitride Materials and Devices XVII
24 January 2022 | San Francisco, California, United States
Gallium Nitride Materials and Devices XVI
6 March 2021 | Online Only, California, United States
Gallium Nitride Materials and Devices XV
4 February 2020 | San Francisco, California, United States
Gallium Nitride Materials and Devices XIV
4 February 2019 | San Francisco, California, United States
Gallium Nitride Materials and Devices XIII
29 January 2018 | San Francisco, California, United States
Gallium Nitride Materials and Devices XII
30 January 2017 | San Francisco, California, United States
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