Veleschuk V. Acoustic emission in light - emitting structures based on the GaP, GaAs and GaN compounds

The thesis are devoted to research of acoustic emission (AE) in semiconductor light-emitting structures based on GaP, GaAs and GaN compounds at flowing of a direct electric current, and acoustic response in GaAs and CdTe single crystals under action of nanosecond pulse of laser radiation on their surface. In thesis the perspective direction of solid state physics connected with use of the acoustic emission phenomenon as purposeful nondestructive method of studying of defect formation dynamics in real time mode in semiconductor structures is developed. By given АЕ method it is received practically important information on processes of natural ageing of light- emitting structures based on the GaAsP, GаP and GaAlAs compounds, which for time 6·108 s. raise the maximal admissible of current density, in particular density of destruction currents and a occurrence АЕ threshold in 10-20 times. For the first time it is shown, that changes in electroluminescence spectrum which traditionally explained with changeof point defect states, correlate with acoustic emission occurrence due to process of reorganization of material structure in local volumes. Melting thresholds of a plane (111) GaAs and CdTe compounds are established at nanosecond laser irradiation on amplitude change of the acoustic response. Keywords: GaP, GaAs, GaN, acoustic emission, defect formation, electroluminescence, laser irradiation.