No abstract

We present a photoluminescence investigation of the electronic properties of a strained GaSb-AlSb quantum well under hydrostatic pressure. Our experiment, performed at liquid-helium temperature, permits us to measure a pressure shift of the quantized exciton smaller than the GaSb band-gap shift. Such an effect is analyzed in the framework of a model calculation which takes account of the nonparabolicity and of the change of the quantized Rydberg (R *) versus pressure. We find 1/R (dR */dP)= -1%/kbar. We estimate a valence-band offset AE, -40 meV.

The chemical preparation of GaSb (001) substrates was performed by Br2-HCI-HN03-CH3COOH solution. The removed layer thickness was evaluated a s a function of the constituent concentrations and the etching time. The surface quality was controlled by SEM, RHEEO and AES. With this treatment, excellent surface morphology of substrates and growth film is obtained.

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Optical functions of GaSc are derived from the Kramers-Kronig analysis of reflectivity data performed at quasi-normal incidence and a t room temperature in the 2 to 80 eV range. Attempts of interpretation are suggested according to recent band structure calculations. In the experimental range, all the valence electrons are excited. On the high energy side, some structure corresponds t o the excitation of 3d-electrons of Ga and Se, respectively. The calculated position of the plasmon peak is in good agreement with energy loss experiments.Les fonctions optiques de GaSe sont calculkes par I'analyse de Kramers-Kronig des mesures de rkflectivitk effectuires sous incidence quasi-normale et A tempirrature ambiante, entre 2 e t 80 eV. Les essais d'interprktation sont b a s h sur de r6cents calculs de structure de bandes. Dans l'intervalle exphimental, tous les 6lectrons de valence sont exciths. Do cSt6 des hautes knergies, la structure correspond A l'excitation des irlectrons 3d de Ga et 3d de Se. La position calculire du pic de plasmon cst en bon accord avec les exphriences dc pertes d'6nergie des klectrons.