Effect of hydrostatic pressure on GaAs-Ga1-xAlxAs microstructures.
Résumé
Some detailed experimental studies of the effect of hydrostatic pressure on the energy levels of GaAs-Ga1−xAlxAs quantum-well heterostructures have been recently published. The heterostructures used are grown by molecular-beam epitaxy and consist of several single GaAs wells with different widths separated by wide Ga1−xAlxAs barriers. Photoluminescence measurements at low temperature and up to 70 kbar show that all the peaks move to higher energy as the pressure is applied. The pressure coefficients of the heavy- and light-hole excitonic transitions appear to be different. On the other hand these coefficients decrease with decreasing well widths. In this paper we present a theoretical calculation of these pressure coefficients and of their well-width and barrier-height dependence, which quantitatively fits the experimental results.