Calculation and experiments
of the cathodoluminescence intensity at p-GaAs.
Influence of beam injection parameters (Eo and Ip)
A. Nouiri1*, A. Djemel1, R.-J. Tarento2
1LPCS, Laboratory Department of Physics, University of Constantine 25000 Algeria
2University of Paris-Sud, Bâtiment 510, 91405 Orsay, France
* Corresponding author. E-mail: firstname.lastname@example.org
Received :03 May 2002; revised version accepted : 30 June 2003
In this model of self-consistent calculation of the cathodoluminescence (CL) intensity, the sample p-GaAs is considered as two regions, depletion and neutral zone. The depletion region is assumed to be the result of the surface charge, which depends on the injection conditions (intensity Ip and energy Eo). The surface recombination is treated in the Shockley-Read-Hall framework. The continuity equations of both majority and minority carriers are solved in the neutral and depletion regions. In this paper we present the variation of CL intensity as a function of electron beam current (Ip) and electron beam energy (Eo) and comparison with experimental data as well as a discussion of relationship of linearity between CL intensity and Ip. Some material parameters, such as defect density Nt at the surface, energy level associated Et and diffusion length Ln are determined from the fitting of theoretical curves to experimental data.
Keywords: Cathodoluminescence; GaAs; Calculation; Surface defects.