2015 / 5

We present the results of experimental studies of the destruction morphology and the spatial distribution of light emission micro-areas on the surface of LED heterostructures InGaN/GaN of different prehistory after multipulse high-current electron beam irradiation. It is shown that local light emission micro-areas, registered on the background of homogeneous cathodoluminescence in textured samples, are formed due to reflection of stimulated emission from local microfractures. It is found that Lichtenberg figures are formed in GaN epitaxial layers with a high dislocation density of 109 cm-2 under multipulse irradiation of electron beam with an energy density H ≈ 0.2 J/cm2. Interpretation of the results is given on the basis of ideas about electric-discharge mechanism of destruction of insulators and semiconductors under the action of high-current electron beams. We suggest that stimulated luminescence effects on the microfractures multiplication during multipulse irradiation of heterostructures by high-current electron beam. Visualization of defective areas due to localization of electrical breakdown in these areas can be the basis of a diagnostic method of electrical microheterogeneities formed in LED heterostructures during growth. Hide Abstract 

Results of theoretical calculation of space-charge waves amplification cutoff frequency fc in thin-film n-InN and n-GaAs semiconductor structures are given in this paper. It is shown that fc is about 200 GHz for indium nitride and 55 GHz for gallium arsenide. Hide Abstract