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(196) Production(s) de BRIOT O.
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BAND OFFSETS AND EXCITON BINDING-ENERGIES IN ZN1-XCDXSE-ZNSE QUANTUM-WELLS GROWN BY METAL-ORGANIC VAPOR-PHASE EPITAXY
Auteur(s): Liaci F., Bigenwald P., Briot O., Gil B., Briot N., Cloitre T., Aulombard R.
(Article) Publié:
Physical Review B, vol. 51 p.4699 (1995)
Ref HAL: hal-00547269_v1
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Résumé: We present a joint study of the band offsets and exciton binding energies in Zn1-xCdxSe-ZnSe quantum wells grown by metal-organic vapor-phase epitaxy with cadmium composition ranging up to 22%. The optical-spectroscopy data presented here are the wavelength derivative of the 2-K reflectance. The strained band-gap difference is divided as follows: the heavy-hole valence-band share deduced from the calculation is 32±1%; the remainder is allotted to the electron conduction band. The exciton binding energy has been calculated within the context of two methods: first, we propose a variational calculation using an exciton wave function written as the product of the envelope-function solutions of the square-well problem with a hydrogenlike two-parameter trial function. Second, as the light-hole potential is marginally type I, we lay out a more sophisticated computation based on a self-consistent variational approach that gives both the exciton binding energies and the self-consistent light-hole densities of probability. We compare the full information given by these two approaches.
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OPTICAL-PROPERTIES, ELECTRONIC-STRUCTURE, AND EXCITON BINDING-ENERGIES IN SHORT-PERIOD ZNS-ZNSE SUPERLATTICES
Auteur(s): Cloitre T., Aigouy L., Diblasio M., Gil B., Bigenwald P., Briot N., Briot O., Bouchara D., Averous M., Aulombard R.
Conference: 36th Electronic Materials Conference (EMC) (Boulder, CO, US, 1994)
Actes de conférence: JOURNAL OF ELECTRONIC MATERIALS, vol. 24 p.123 (1995)
Ref HAL: hal-00547268_v1
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Résumé: We present a detailed examination of the optical properties and electronic structure taken from photoreflectance and photoluminescence data collected on a series of short-period ZnS-ZnSe superlattices grown by low pressure metalorganic vapor phase epitaxy. We studied the band offset problem and calculated the exciton binding energy using several variational models. The temperature dependence of the photoluminescence properties of these superlattices was analyzed in the context of a model which includes the influence of the interfacial disorder.
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Critical layer thickness in MOCVD grown InGaAs-GaAs strained quantum wells
Auteur(s): Zhang Xb, Briot O., Gil B., Aulombard R.
Conference: 1st International Conference on Low Dimensional Structures and Devices (Singapore, SG, 1995)
Actes de conférence: MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY, vol. 35 p.184 (1995)
Ref HAL: hal-00547105_v1
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Résumé: A series of In0.14Ga0.86As-GaAs quantum well structures have been grown by metal organic chemical vapor deposition (MOCVD). The measured dependence of photoluminescence (PL) energies on well width is compared with calculation. By the energy shift, line width and intensity change of PL spectroscopy, critical layer thickness has been identified. The critical layer thickness obtained for MOCVD grown material was found in agreement with theoretical value, but is smaller than molecular beam epitaxy grown ones.
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Exciton recombination mechanism and binding energies in MOCVD-grown Zn1-xCdxSe-ZnSe single quantum wells.
Auteur(s): Liaci F., Aigouy L., Bigenwald P., Gil B., Briot N., Cloitre T., Briot O., Aulombard R.
Conference: IV International Conference on Optics of Excitons in Confined Systems (Cortona, IT, 1995)
Actes de conférence: NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA D-CONDENSED MATTER ATOMIC MOLECULAR AND CHEMICAL PHYSICS FLUIDS PLASMAS BIOPHYSICS, vol. 17 p.1585 (1995)
Ref HAL: hal-00547074_v1
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Résumé: We report here on the study of the optical properties of ZnCdSe-ZnSe quantum structures elaborated by metalorganic chemical vapour deposition (MOCVD). The band structure is experimentally investigated by means of photoluminescence and photoreflectance. We have computed the exciton binding energies for heavy- and light-hole excitons in the context of a self-consistent two-parameter trial function. As a complement, we study the temperature dependence of the photoluminescence intensity under both direct and indirect photoexcitation in graded-index separate confinement heterostructures based on these materials.
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RAMAN-STUDY OF BAND BENDING AT ZNSE/GAAS INTERFACES
Auteur(s): Pagès O., Renucci Ma, Briot O., Aulombard R.
(Article) Publié:
Journal Of Applied Physics, vol. 77 p.1241 (1995)
Ref HAL: hal-00547270_v1
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Résumé: Apparent p‐type conductivity in nonintentionally doped ZnSe layers, grown at high temperature on semi‐insulating GaAs substrates, is investigated by Raman spectroscopy. The microprobe technique provides direct evidence for carrier location on the GaAs side of the structures, close to the interface. Line‐shape analysis of the coupled LO phonon‐plasmon mode for different exciting wavelengths can be achieved, within the model of Hon and Faust [Appl. Phys. 1, 241 (1973)], only when incorporating plasma inhomogeneity. Electronic band bending at the junction in GaAs is deduced from the inferred carrier‐density profile. Changes in Raman spectra under strong illumination are shown to proceed from the flattening of the bands through selective carrier photoinjection.
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EXCITONS AND BIEXCITONS IN MOVPE-GROWN ZNS EPITAXIAL LAYERS
Auteur(s): Guennani D., Valenta J., Manar A., Grun J.B., Cloitre T., Briot O., Aulombard R.
(Article) Publié:
Solid State Communications, vol. 96 p.637 (1995)
Ref HAL: hal-00547267_v1
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Résumé: High quality MOVPE-grown ZnS/GaAs epilayers are characterized by reflection, transmission and linear photoluminescence (PL) spectroscopy at 2 K. The GaAs substrate of a part of each ZnS layer is removed and the optical properties of as-grown and etched surfaces are compared. The splitting (caused by the thermally induced strain) of the topmost Gamma(8) valence band into the heavy and light-hole subbands (Delta(hl)=4 meV) and the transitions involving exciton ground and excited states are better seen in PL excitation spectra than in ordinary PL spectra. From the analysis of the nonlinear PL and PL excitation spectra, we can conclude the existence of biexcitons with a binding energy of about 10 to 12 meV under an intermediate intensity of excitation (a density of about 2.5x10(16) to 2.5x10(17) e-h excited pairs per cm(3)).
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HIGH-FIELD DIRECT-CURRENT CONDUCTION IN EPITAXIAL ZNS FILMS
Auteur(s): Bringuier E., Briot O.
(Article) Publié:
Applied Physics Letters, vol. 67 p.3486 (1995)
Ref HAL: hal-00547264_v1
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Résumé: The current-voltage characteristic of a semiinsulating, monocrystalline ZnS film grown by metalorganic vapor-phase epitaxy is reported. High-field conduction is found to occur in the same field range (1.0-1.5 MV/cm) as in highly defected, electroluminescent material. It is concluded that the conduction mechanism underlying the operation of ZnS-based electroluminescent devices is bulk controlled.
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