Coupled LO-plasmon modes in semi-insulating GaAs of ZnSe/GaAs heterojunctions

O. Pagès (1) , Ma Renucci , Olivier Briot (2) , Roger Aulombard (2)

1 Laboratoire Physique des Solides de Toulouse
2 GES - Groupe d'étude des semiconducteurs

Raman spectroscopy is used to investigate strong band bending at the interface in semi-insulating substrates of ZnSe/GaAs heterostructures grown at high epitaxy rates. Direct evidence is given of the enhancement of polar modes strength, on the substrate side, by the electric field of the space-charge zone associated with Fermi-level pinning. The latter is qualitatively analyzed by following band flattening under illumination through the evolution of interfacial coupled LO-phonon-plasmon modes. Corresponding Raman line shapes are discussed within the phenomenological approach of D. H. Hon and W. L. Faust [Appl. Phys. 1, 241 1 (1973)].

Domaines: Science des matériaux [cond-mat.mtrl-sci]

O. Pagès, Ma Renucci, Olivier Briot, Roger Aulombard. Coupled LO-plasmon modes in semi-insulating GaAs of ZnSe/GaAs heterojunctions. Journal of Applied Physics, 1996, 80 (2), pp.1128. ⟨hal-00547055⟩