Wagner, J.J.WagnerSchmitz, J.J.SchmitzFuchs, F.F.FuchsRalston, J.D.J.D.RalstonKoidl, P.P.KoidlRichards, D.D.Richards2022-03-032022-03-031995https://publica.fraunhofer.de/handle/publica/18644610.1103/PhysRevB.51.9786We have used resonant Raman scattering to study intersubband transitions InAs/AlSb quantum wells. For optical excition in resonance with E1 band gap of InAs, both high- and low-frequency coupled longitudinal-optical phonon-intersubband plasmon modes are observed. From the measured energies of these plasmon modes the single-particle transition energies between the first and second confined electron subband were deduced as a function of the InAs well width. Good agreement was found with subband spacings predicted by theory including the effects of strain and nonparabolicity. InAs/AlSb surface quantum wells, where a pseudomorphically strained InAs quantum well is grown on an AlSb buffer layer without an AlSb top barrier, also show well-resolved intersubband plasmon modes, indicating higher-electron mobilities than those typically found in the surface inversion region of thick InAs layers.enInAs/AlSb quantum wellintersubband transitionIntersubband-Übergangraman scatteringRamanstreuung621667530journal article