Analytical perturbation derivation of the exciton binding energy in generalized infinite quantum wells: Application to type-I and -II finite-quantum-well structures

AbstractWe report on detailed luminescence studies of MBE grown Si/Si1-xGex quantum well structures. Both well width and composition is varied over a wide range. Bandgap photoluminescence is observed for all samples grown at elevated temperatures. The measured bandgap energies are in good agreement with subband calculations based on effective mass approximation and taking into account the segregation of Ge atoms during growth. Diffusion is found to limit quantum well (QW) growth with Ge-contents above 35% at high temperatures. The photoluminescence signals are detected up to about 100K and can be attributed to interband transitions of free excitons. We also present investigations of the exciton binding energy as a function of well width and composition. The observed shift of the exciton binding energy is compared with results of a variational calculation. A distinct onset in photocurrent and electroluminescence up to 200 K are observed in quantum well diodes.

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Determination of Exciton Binding Energy of GaInNAs Quantum Well Structures by Piezoelectric Photothermal Spectroscopy Compared with Photoreflectance Measurements

Japanese Journal of Applied Physics ◽

10.7567/jjap.50.06gh09 ◽

2011 ◽

Vol 50 (6S) ◽

pp. 06GH09 ◽

Cited By ~ 2

Author(s):

Koshiro Kashima ◽

Atsuhiko Fukuyama ◽

Kentaro Sakai ◽

Hirosumi Yokoyama ◽

Masahiko Kondow ◽

...

Keyword(s):

Binding Energy ◽

Quantum Well ◽

Exciton Binding Energy ◽

Photothermal Spectroscopy ◽

Quantum Well Structures

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Theory of magneto-exciton binding energy in realistic quantum well structures

Solid State Communications ◽

10.1016/0038-1098(88)90233-5 ◽

1988 ◽

Vol 68 (1) ◽

pp. 1-5 ◽

Cited By ~ 28

Author(s):

D.M. Whittaker ◽

R.J. Elliott.

Keyword(s):

Binding Energy ◽

Quantum Well ◽

Exciton Binding Energy ◽

Quantum Well Structures

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Conduction edge strain splitting in Ge-Si quantum wells using EELS

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010014991x ◽

1993 ◽

Vol 51 ◽

pp. 816-817

Author(s):

P.E. Batson ◽

J.F. Morar

Keyword(s):

Quantum Well ◽

Quantum Wells ◽

Conduction Band ◽

Lattice Mismatch ◽

Axial Strain ◽

Band Edge ◽

Reference Level ◽

Conduction Band Edge ◽

Type I ◽

Quantum Well Structures

Ge/Si quantum well structures show a high hole mobility as the heavy hole bands are shifted to lower energy under bi-axial strain produced by lattice mismatch between the well and the Si substrate. This strain can also split and shift the conduction band edge in the well to below that of Si, producing a Type I quantum well capable of photo-luminescence. In previous work, we have shown that the conduction bandstructure can be obtained using EELS in the relaxed Ge/Si alloy system. Also, we have noticed that the heterojunction band offset can be obtained from EELS because the Si 2p core level is a constant energy reference level throughout the alloy composition. In this report, we show that a detailed fitting of the shape of the Si L2,3 edge can obtain the bi-axial strain splitting of the conduction band edge as a function of position inside a quantum well. This information can then be correlated with annular dark field images of the cross sectioned well.

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SHALLOW DONORS IN A COUPLED TRIPLE GRADED QUANTUM WELL UNDER THE ELECTRIC AND MAGNETIC FIELDS

Surface Review and Letters ◽

10.1142/s0218625x06008360 ◽

2006 ◽

Vol 13 (04) ◽

pp. 397-401 ◽

Cited By ~ 13

Author(s):

E. KASAPOGLU ◽

H. SARI ◽

I. SÖKMEN

Keyword(s):

Binding Energy ◽

Quantum Well ◽

Quantum Wells ◽

Electric Fields ◽

Growth Direction ◽

Physical Parameters ◽

Donor Impurity ◽

Quantum Well Structures ◽

Hydrogenic Donor Impurity ◽

Electric And Magnetic Fields

The binding energy of the donor in three different shaped triple graded GaAs -( Ga , Al ) As quantum wells which is obtained by changing the depth of the central-well potential (Vo) is calculated by using a variational approach. The results have been obtained in the presence of uniform magnetic and electric fields applied along the growth direction as a function of the impurity position. In addition, we also give the binding energy of the hydrogenic donor impurity for triple square quantum wells having the same physical parameters with triple graded quantum well structures in order to see the effect of different geometric confinements on the donor impurity binding energy.

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Exciton Binding Energy as a Function of Barrier Width in Coupled Quantum Well Structures

Chinese Physics Letters ◽

10.1088/0256-307x/9/2/011 ◽

1992 ◽

Vol 9 (2) ◽

pp. 93-96

Author(s):

Shi Junjie ◽

Pan Shaohua

Keyword(s):

Binding Energy ◽

Quantum Well ◽

Exciton Binding Energy ◽

Barrier Width ◽

Quantum Well Structures ◽

Coupled Quantum Well

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OMVPE Growth of GalnAs/InP Quantum Well Structures

MRS Proceedings ◽

10.1557/proc-102-515 ◽

1987 ◽

Vol 102 ◽

Cited By ~ 1

Author(s):

G. B. Stringfellow

Keyword(s):

Binding Energy ◽

Quantum Well ◽

Quantum Wells ◽

Vapor Phase ◽

Atmospheric Pressure ◽

Growth Conditions ◽

Binding Energies ◽

Optimum Conditions ◽

Quantum Well Structures ◽

Maximum Value

ABSTRACTInP/GalnAs/InP quantum well structures have been grown using atmospheric pressure organometallic vapor phase epitaxy (AP-OMVPE). The optimum conditions for growth of extremely abrupt interfaces were studied. The optimum orientation was exactly (100). The growth had to be interrupted for 40 seconds at the first interface and 2 minutes at the 2nd interface to obtain the most abrupt interfaces. The narrowest photoluminescence half widths were obtained at the lowest values (31) of V/III ratio in the input vapor phase. These growth conditions allow the growth of wells as thin as <10Å with photoluminescence (PL) spectra consisting of doublets or triplets. The extremely narrow peaks correspond to regions of the quantum well differing in thickness by a single monolayer. The energy separations of the neighboring peaks are found to increase with decreasing well width until, at a thickness of approximately 12 Å, the separation begins to decrease rapidly with decreasing well width. The exciton binding energies in the quantum wells have also been measured using thermally modulated PL. The binding energy is found to increase with decreasing well width until a maximum value of approximately 17 meV is measured for a nominal well width of approximately 13 Å. For thinner wells the exciton binding energy is found to decrease with decreasing well width.

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