Study of the structural, optical and electrical properties of extended defects in GaN

The aim of the project is the study of the role and the distribution of extended defects in thin films of Gallium Nitride grown by different procedures. The project was developed on GaN samples chracterizaed by means of the following techniques: - HR- TEM (High Resolution Transmission Electron Microsopy) analyses for structural characterization - EBIC ( Electron Beam Induced Current) for electrical characterization of extended defects - spectroscopical techniques (CL-TEM, spectral photoconductivity, micro-Raman and micro-photoluminescence. The findings allowed for confirming many hypotheses concerning: - the radiative character of dislocation-associated defects; - the recombination probability at dislocation-induced deep levels - the strong correlation between structural and electrical properties - the correlation among growth conditions, doping and extended defect density; - the influence of dislocations on the charge carrier transport.