MAGNETOTRANSPORT, MAGNETOOPTICAL AND ELECTRONIC SUBBAND STUDIES IN HIGHLY STRAINED INXGA1-XAS INP ONE-SIDE-MODULATION-DOPED DOUBLE-QUANTUM WELLS/

Shubnikov-de Haas (SdH), Van der Pauw Hall effect and cyclotron resona nce measurements on InxGa1-xAs/InP asymmetric double quantum wells gro wn by metalorganic chemical vapour deposition have been carried out to investigate the magnetotransport properties of an electron gas and to determine the effective mass of the electron gas, subband energies an d wavefunctions in the quantum well. Transmission electron microscopy measurements show that a 50 Angstrom InAs and a 100 Angstrom In0.53Ga0 .47As quantum well were separated by a 30 Angstrom In0.25Ga0.75As pote ntial barrier in an active region. The SdH measurements at 1.5 K demon strated clearly the existence of a quasi-two-dimensional electron gas (2DEG) in the quantum wells. The fast Fourier transformation results f or the SdH data indicate clearly the electron occupation of two subban ds in the InxGa1-xAs/InP double quantum wells. The results of the cycl otron resonance measurements show that one absorption resonance is evi dence of electron concentration occupied at the ground state subband i n the double quantum well. The electron effective mass determined from the slope of the main peak absorption energies as a function of a mag netic field is 0.0493m(e). Electronic subband energies and energy wave functions in the quantum wells were calculated by a self-consistent me thod taking into account exchange correlation effects together with st rain and non-parabolicity effects. The ground state subband wavefuncti on is strongly localized in the InAs quantum well side, and the first excited subband wavefunction in the asymmetric quantum well is very we akly coupled over both InAs and In0.53Ga0.47As wells.