Band offset in elastically strained InGaAs/GaAs multiple quantum wells determined by optical absorption and electronic Raman scattering

Abstract

Pseudomorphic InGaAs/GaAs multiple quantum well structures with In contents ranging from 18 to 25% were grown by molecular beam epitaxy and investigated by optical absorption, photoluminescence, and electronic Raman scattering. Sharp exciton peaks with linewidths of ∼3 meV for the first electron to heavy hole transition are observed in the absorption spectra. The electron subband structure was investigated independently by electronic Raman scattering. The transition energies are analyzed using a four-band effective mass Schrödinger equation taking strain into account. A conduction-band offset ratio ΔEc/ΔEg=0.6 is found for all samples independent of In content.

Optical properties and band bending of InGaAs/GaAsBi/InGaAs type-II quantum well grown by gas source molecular beam epitaxy

“…In the calculations reported in this paper, band offset ratios of 60:40 between the strained InGaAs and GaAs and 24:76 between the strained GaAsBi and GaAs were used, respectively. 6,31 The transformation of GaAsBi and In 0.2 Ga 0.8 As to form a type-II configuration from a type-I configuration is estimated to occur near a Bi concentration of 1.3%. A schematic diagram of the conduction and valence bands in the active region of our structure is shown in Fig.…”

Raman spectroscopy of wurtzite and zinc-blende GaAs nanowires: Polarization dependence, selection rules, and strain effects

“…It has been developed to be a versatile tool for the characterization of semiconductors leading to detailed information on crystal structure, phonon dispersion, electronic states, composition, strain and so on of semiconductor nanostructures or nanowires. [18][19][20][21][22][23][24][25][26] More recently Raman spectroscopy has been used extensively to study also nanowires and quantum dots. 27,28 Several phenomena have been reported to date with respect to one-dimensional structures.…”

Wannier–Stark localization in a strained InGaAs/GaAs superlattice

“…2 is similar to the previous results obtained in the GaAsl AIGaAs system,4 except our Mo exciton is better defined, and since the strain lifts the light hole to higher energies, only the peaks due to the heavy hole transitions are observed. Using the values of Reithmaier et al 12 for band discontinuities, strain, and effective masses, transmission matrix calculations predict the presence of an electron miniband about 35 meV wide at zero field. Although we cannot probe the zero field case experimentally, the built-in field of the diode can be reduced by a small forward bias, or leaving the terminals open circuited under illumination.…”