Modulation spectroscopy under uniaxial stress

Photoreflectance ͑PR͒ spectroscopy, x-ray diffraction ͑XRD͒ method, and secondary ion mass spectroscopy ͑SIMS͒ were used to observe the radial distribution of the band-edge transition and modification of the band structure due to the variation of indium in 3 in. indium-alloyed semi-insulating GaAs (In x Ga 1Ϫx As) grown by the liquid-encapsulated Czochralski method. The data from room temperature PR measurements showed the variation of the transition energy with positions indicating the radial distribution of the indium content across the wafers; indium content being higher around the edge region than the central area. The splitting of the degenerate valence band around the edge region of the wafers was also shown in PR data due to the different indium content in adjacent regions where indium content varies rapidly. The XRD measurements showed the drastic change in the distribution of lattice constant on where the splitting of the heavy and light holes happened and the SIMS analysis was adopted to confirm the distribution of indium content across the wafer. The possible model was proposed from the experimental data.

Section: ͑1͒contrasting

confidence: 45%

Section: Methodsmentioning

confidence: 99%

Splitting of the heavy and light hole bands due to the indium-induced strain in three inch indium-alloyed semi-insulating GaAs substrates

Kim

2000

“…The LH valence band has a nonlinear strain dependence because of the strain-induced coupling with the spin-orbit-split band. 15 Since for InGaAs/GaAs Ͻ0, the effect of the lattice mismatch strain is to increase the energy gap of the InGaAs ͑hydrostatic-pressure component͒ and split the degeneracy of the valence-band edge at the center of the Brillouin zone, so that the HH band moves up and the LH band moves down, relative to the unstressed valence band.…”

Section: Resultsmentioning

confidence: 99%

Temperature dependent surface photovoltage spectroscopy characterization of highly strained InGaAs/GaAs double quantum well structures grown by metal organic vapor phase epitaxy

Chan

Huang

et al. 2009

Articles you may be interested inStrain-compensation measurement and simulation of InGaAs/GaAsP multiple quantum wells by metal organic vapor phase epitaxy using wafer-curvature J. Appl. Phys. 110, 113501 (2011); 10.1063/1.3663309 Erratum: "Size-dependent photoluminescence of hexagonal nanopillars with single InGaAs/GaAs quantum wells fabricated by selective-area metal organic vapor phase epitaxy" [Appl. Phys. Lett. 89, 203110 (2006)] Appl. Phys. Lett. 92, 059901 (2008); 10.1063/1.2841828 Spectroscopic characterization of 1.3 μ m GaInNAs quantum-well structures grown by metal-organic vapor phase epitaxy Appl. Phys. Lett. 86, 092106 (2005); 10.1063/1.1868866Effect of growth temperature on strain barrier for metalorganic vapor phase epitaxy grown strained InGaAs quantum well with lattice matched InGaAsP barriers Photoluminescence microscopy imaging of tensile strained In 1−x Ga x As y P 1−y / InP quantum wells grown by low-pressure metalorganic vapor phase epitaxy Highly strained In x Ga 1−x As/ GaAs double quantum well ͑DQW͒ structures grown by metal organic vapor phase epitaxy with different In compositions are investigated by surface photovoltage spectroscopy ͑SPS͒ in the temperature range 20-300 K. A lineshape fit of spectral features in the differential surface photovoltage ͑SPV͒ spectra determines the transition energies accurately. A comprehensive analysis of the anomalous phenomena appearing in lower temperature SPV spectra enable us to evaluate directly the band lineup of DQW and to remove the ambiguity in the identification of spectral features. The process of separation of carriers within the QW with possible capture by the interface defect traps plays an important role for phase change in SPV signal in the vicinity of light-hole related feature at low temperature. The results demonstrate the considerable diagnostic values of the SPS technique for characterizing these highly strained DQW structures.

“…According to Pollack, 12 stants͒, and c i j the elastic stiffness constants. Theoretical approach makes use of the envelope-function method, within the effective mass approximation, and includes the strain.…”

Section: Discussionmentioning

confidence: 99%

Photovoltaic spectroscopy of exciton structures in Zn1−xCdxSe/ZnSe multiple quantum wells

Anedda

Casu

Serpi

1996

Exciton transitions in photovoltaic spectra of strained-layer multiple-quantum-well samples of Zn 1Ϫx Cd x Se/ZnSe grown by molecular-beam epitaxy were observed up to room temperature. Quantum level energies were calculated by means of the envelope-function method including strain. Great care was taken in order to evaluate the band offsets, the band-gap dependence on temperature and alloy concentration, as well as the quantum confinement enhancement of the exciton binding energies. Very good agreement between experimental and calculated values of the exciton energy position was found in the 80-300 K temperature range. Calculated binding energies as high as 35-40 meV account for the occurrence of the exciton structures up to 300 K.