Interdiffusion in InGaAs/GaAs strained quantum wells

• Main Author: Gillin, W. P.
• Published: University of Surrey 1991
• Subjects: 530.1; Theoretical physics
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303221

This thesis presents the results of a study of the interdiffusion of InGaAs/GaAs structures. Photoluminescence in conjunction with a model for the interdiffusion has been used to show that the diffusion obeys Fick's law and that there are two distinct diffusion regions. The first is a fast initial diffusion, which is suggested to be caused by the diffusion of point defects in the quantum well, and which is found to occur solely during the first anneal. The second is a steady state diffusion region during which the diffusion coefficient is constant. The steady state diffusion coefficient has been shown to be dependent upon the distance of the quantum well from the surface and upon the incorporation of silicon in the material. The indium concentration of the initial well has been shown to have no effect on the diffusion coefficient as has beryllium doping. An activation energy for the diffusion of 3.0 +/- 0.3 eV has been obtained in all cases.