Effects of band offset and nonparabolicity on the effective mass of two-dimensional electron gases in modulation-δ-dopedGa0.47In

Abstract

We present an investigation of electronic and optical properties of two-dimensional electron gases confined in modulation-␦-doped Ga 0.47 In 0.53 As-based heterostructures by Shubnikov-de Haas measurement and optically detected cyclotron resonance ͑ODCR͒. Quantum oscillations clearly show the occupation of the first two subbands. The values of the effective masses obtained from ODCR measurements are considerably higher than the bulk data by 20-50 %. The theoretical prediction of the effect of nonparabolicity is insufficient to explain the experimental results. By choosing heterostructures with a very large difference in the conduction-band offset, we clearly show that this discrepancy can be attributed to the effect of wave-function penetration into the barrier material. ͓S0163-1829͑97͒02608-8͔

Magnetotransport in modulation-doped In0.53Ga0.47As/In0.52Al0.48As heterojunctions: in-plane effective mass, quantum and transport mobilities of 2D electrons

“…48 As barrier/spacer layer have no significant effects on m * of 2D electrons in our samples. However, the values obtained for m * of electrons in the second subband of the samples with t S = 0 and 100 Å are somewhat smaller than that (=(0.045 ± 0.003)m 0 ) found [15,32] for electrons in the second subband of δ-doped In 0.53 Ga 0.47 As/In 0.52 Al 0. 48 As heterojunctions with t S = 60 Å.…”

Tunable two-dimensional plasmon resonances in an InGaAs/InP high electron mobility transistor

“…͑5͒ using AlAs = 10.2, InAs = 14.6, and GaAs = 13.1.͔ An effective mass m ‫ء‬ = 0.043 is taken for the electrons in the InGaAs channel, 11 although the actual value may be as much as 50% higher due to wave-function bleeding into the InAlAs barrier material. 12 We note that the room temperature zero-bias value of mobility, = 7250 cm 2 / V s is smaller than both our own Hall value of 11 331 cm 2 / V s and that specified by the manufacture of 10 100 cm 2 / V s. Saturation current and Hall measurements are performed for very different biasing conditions, which can easily explain the difference. The n d value of 9.3ϫ 10 11 cm −2 is ϳ4ϫ less than the nominal delta-doping level value of 4 ϫ 10 12 cm −2 .…”

Tunable far-IR detectors/filters based on plasmons in two-dimensional electron gases in InGaAs/InP heterostructures

“…7 illustrates the effects of sheet charge and effective mass uncertainty at 4 K, where the sheet charge density of 2.4 x 10 12 cm -1 is varied by a factor of two, while the effective mass of 0.043 is increased by 50% to 0.065. 12 With these changes in material parameters no change is seen in the plasmon FWHM of ~1.0 cm -1 . Changing the effective mass by 50% however causes a 19% decrease in the peak position wave number.…”