L'effet de la température dans la technique cathodoluminescence par la methode Monte Carlo

Abstract

In the present work, we have elaborated a numerical model to study a semiconductor doped the type p(p- GaAs) using the Monte Carlo method. This model treat the electron- matter interaction, particularly, the cathodoluminescence technique. The calculation procedure take into a count the random walk of the electron inside the material and the influence of the electron beam parameters (number of electrons Nel,accelerating energy E0). The description of the elastic scattering is based on the modified screened Rutherford differential cross section. The major problem treated in this these is the temperature rise (ΔT) which is due to the electron beam bombardment. The influence of ΔT on cathodoluminescence signal is also studied. The calculation results show that ΔT is high at the surface, then it decreases (exponentially) as a function of depth. The ΔT depends also on beam parameters (absorbed current Ip and accelerating energy E0). ΔT increases with increasing of (electron number), contrarely, ΔT decreases with increasing of accelerating energy. Concerning the CL signal, there is no influence on CL intensity for the weak beam currant Ip ,but for the high Ip ( >10-13A) case, we remarked that CL intensity decreases with increasing of ΔT, particularly in the weak accelerating energy E0. Our theoretical results are compared with the available experimental data and other theoretical results. This comparison leads to can be deduce values for different physical parameters,( diffusion length Ln , absorption coefficient α ), and the great coherent between these models.