The mechanisms of size-dependent efficiency and efficiency droop of blue InGaN micro-pixel light emitting diodes (LEDs) have been investigated experimentally and by simulation. Electrical characterisation confirms the improvement of current spreading for smaller LEDs, which enables the achievement of the higher efficiency at high injection current densities. Owing to the higher ratio of sidewall perimeter to mesa area of smaller LEDs, a lower efficiency was observed at a low injection current density, resulting from defect-related Shockley-Read-Hall non-radiative recombination. We demonstrate that such sidewall etch defects can be partially recovered by increased thermal annealing time, consequently improving the efficiency at low current densitie

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The radiologic criteria that should be used for assessment of RLN metastases in NPC patients are nodes with a minimal axial diameter 6 mm or larger, any node with central necrosis, groups of two or more RLNs, or any medial RLN; these criteria may be useful in tumor staging and treatment planning.

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A sample of the β-Ga2O3/wurtzite GaN heterostructure has been grown by dry thermal oxidation of GaN on a sapphire substrate. X-ray diffraction measurements show that the β-Ga2O3 layer was formed epitaxially on GaN. The valence band offset of the β-Ga2O3/wurtzite GaN heterostructure is measured by X-ray photoelectron spectroscopy. It is demonstrated that the valence band of the β-Ga2O3/GaN structure is 1.40 ± 0.08 eV.