Γ - Xx Mixing In Gaas-g A1-xa Lxas Quantum Wells Under Hydrostatic Pressure

The mixing between the Γ and X conduction-band valleys in GaAs-Ga 1-xAl xAs quantum wells is investigated by using a phenomenological model which takes into account the effects of applied hydrostatic pressure. The dependencies of the variationally calculated photoluminescence peak-energy transitions on the applied hydrostatic pressure and quantum-well width are presented. A systematic study of the Γ-X mixing parameter is also reported. In particular, it is shown that the inclusion of the Γ-X mixing explains the non-linear behavior in the photoluminescence peak of confined exciton states that has been experimentally observed for pressures above 15 kbar in GaAs-Ga 1-xAl xAs quantum wells. © 2008 EDP Sciences/Società Italiana di Fisica/Springer-Verlag.623257261Ando, T., Akera, H., (1989) Phys. Rev. B, 40Pulsford, (1989) Phys. Rev. Lett., 63, p. 2284Wang, (1992) Phys. Rev. B, 46, p. 7304Liu, (1987) Appl. Phys. Lett., 51, p. 1019Sun, (1993) J. Appl. Phys., 74, p. 5053Brzostowski, (2003) Phys. Rev. B, 67, p. 125305Shan, (1991) Phys. Rev. B, 43, p. 14615Li, (1996) Phys. Rev. B, 54, p. 13820Neethiulagarajan, (1993) Phys. Rev. B, 48, p. 9114(1994) Proceedings of the 6th International Conference on High Pressure Semiconductor Physics, , Vancouver(1995) J. Phys. Chem. Solids, 56 (3-4). , references thereinMora-Ramos, (2006) Braz. J. Phys., 36, p. 866Venkateswaran, (1986) Phys. Rev. B, 33, p. 8416Burnett, (1993) Phys. Rev., 47, p. 1991Tischler, (2000) Physica e, 6, p. 177Li, (1994) Phys. Rev. B, 50, p. 18420Bednarek, (1995) Phys. Rev. B, 51, p. 4687Tomić, (2004) Phys. Rev. B, 69, p. 245305Dios-Leyva, (2001) J. Phys.: Condens. Matter, 13, p. 9471López, S.Y., Porras-Montenegro, N., Duque, C.A., (2003) Phys. Stat. Sol. (C), p. 648Raigoza, (2004) Phys. Rev. B, 69, p. 045323Li, (2000) Physica e, 5, p. 215Xang, (1993) Phys. Rev. B, 48, p. 2465Niculescu, (1996) Phys. Lett. A, 213, p. 85The energy shift, in the theoretical calculations, is defined as the difference [e 1(P=0)+h 1(P=0)+E b(P=0)]-[e 1(P)+h 1(P)+E b(P)]. For the experimental data this energy shift is obtained as the difference PL peak (P=0)-PL peak(P)- β(GaAs})