Cathodoluminescence Characterization: Applications on Nitrides

This work presents a two-dimensional computational model of cathodoluminescence (CL) intensity that takes into account the lateral and depth scattering of generated carriers, internal absorption (alpha), rate of generation, intrinsic and extrinsic radiative recombination mechanisms, and experimental conditions of electron excitation. An experimental study on GaN using this technique is presented followed by a comparison and validation. The study of the influence of some physical parameters such as scattering length, surface recombination velocity of minority carriers and absorption coefficient on the intensity of LC. Emphasis was placed on the dependence of the LC signal on excitation parameters. To interpret the experimental results and validate our model we studied the effect of stress and the thermal effect accompanying the electronic excitation on the fundamental peak evolution of CL. This study also allowed us to explain the variation in LC intensity with competitive alpha phenomena, the local effect of temperature and the effect of stresses present in the material.