Electron and hole effective masses from magnetoluminescence studies of modulation-doped InP/In0.53Ga0.47As heterostructures

Two-dimensional (2D) carrier-recombination processes in modulation-doped unstrained InP/${\mathrm{In}}_{0.53}$ ${\mathrm{Ga}}_{0.47}$As heterostructures with 500-Å-wide ${\mathrm{In}}_{\mathit{x}}$ ${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As active layers have been investigated with magneto-optical spectroscopy. Photoluminescence bands related to the 2D confined carriers have been observed in both n- and p-type modulation-doped structures. For the n-type structures it is found that the emissions observed are transitions between 2D electrons at the interface potentials and holes in the ${\mathrm{In}}_{\mathit{x}}$ ${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As valence band. Excitonic effects are not observed, even for the emission related to the third confined electronic state. For the p-type structures the transitions occur across the ${\mathrm{In}}_{\mathit{x}}$ ${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As layer between 2D holes and 2D electrons at the opposite interface notch potentials. Both the n- and the p-type modulation-doped structures show well-resolved Landau-level splitting when a magnetic field is applied parallel to the growth direction. The effective masses of both 2D electrons and 2D holes confined in the ${\mathrm{In}}_{\mathit{x}}$ ${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As layer are simultaneously obtained by analysis of the same magneto-optical data. Effective-mass values of ${\mathit{m}}_{\mathit{e}}$=(0.054±0.005)${\mathit{m}}_0$ for the first subband electrons and ${\mathit{m}}_{\mathrm{hh}}$=(0.463±0.005)${\mathit{m}}_0$ for the first subband heavy holes, respectively, are derived from our spectra. The effective mass of n=2 subband electrons was found to be about 9% larger than the effective mass of n=1 electrons.