Hangyang Chen

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High internal efficiency and high temperature stability ultraviolet (UV) light-emitting diodes (LEDs) at 308 nm were achieved using high density (2.5 × 10(9) cm(-2)) GaN/AlN quantum dots (QDs) grown by MOVPE. Photoluminescence shows the characteristic behaviors of QDs: nearly constant linewidth and emission energy, and linear dependence of the intensity(More)
According to first-principles calculations, the solubility of Mg as a substitute for Ga or Al in AlxGa1 - xN bulk is limited by large, positive formation enthalpies. In contrast to the bulk case, the formation enthalpies become negative on AlxGa1 - xN surface. In addition, the N-rich growth atmosphere can also be favorable to Mg incorporation on the surface(More)
Ultra-short-period (AlN)m/(GaN)n superlattices with tunable well and barrier atomic layer numbers were grown by metal-organic vapour phase epitaxy, and employed to demonstrate narrowband deep ultraviolet photodetection. High-resolution transmission electron microscopy and X-ray reciprocal space mapping confirm that superlattices containing well-defined,(More)
The vacuum Rabi splitting of exciton-polariton emission is observed in cathodoluminescence (CL) and photoluminescence spectra of an AlN epitaxial film. Atomic force microscopy and CL measurements show that the film has an atomically flat surface, high purity, and high crystal quality. By changing the temperature, anticrossing behavior between the upper and(More)
A nanoscale non-contact electrical measurement has been developed based on Auger electron spectroscopy. This approach used the specialty of an Auger electron, which is self-generated and free from external influences, to overcome the technical limitations of conventional measurements. The detection of the intrinsic local charge and internal electric field(More)
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