Specific features in the temperature dependence of photoluminescence from CdTe/ZnTe size-quantized islands and ultrathin quantum wells

Зайцев, В. В.; Багаев, В. С.; Onishchenko, E. E.

doi:10.1134/1.1130842

Cited by 13 publications

(8 citation statements)

References 27 publications

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“…As a rule, the larger activation energy E 2 is related to the high temperature emission intensity. 16 A similar behavior of two activation energies below and above 70 K was reported by Fonoberov et al for ZnO quantum dots. 17 Generally, the temperature dependence of the PL linewidth reveals different scattering mechanisms.…”

supporting

confidence: 80%

Free exciton emission and dephasing in individual ZnO nanowires

Yang

Chen

Lee

2007

Applied Physics Letters

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We report on systematic measurements of the dephasing of the free excitonic transition in individual ZnO nanowires with a diameter of about 70 nm. The temperature-dependent intensity of the free exciton ͑FX͒ emission is well reproduced by a thermally activated behavior having two constant activation energies of 5.98 and 30.63 meV. The FX linewidth broadening with temperature reveals the dephasing of FX scattered by acoustic phonons rather than longitudinal optical phonons. These findings indicate that the dephasing mechanism scattering from acoustic phonons in individual ZnO nanowires result from the compensation of acoustic phonons to the nonconservation of crystal momentum.

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supporting

confidence: 80%

Free exciton emission and dephasing in individual ZnO nanowires

Yang

Chen

Lee

2007

Applied Physics Letters

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“…Thus, change of the structure strain state really can change the band diagram type. The PL band peak position shift with increasing temperature for the B0 and B50 samples -in contrast to similar samples studied earlier [6,7] -exceeds ZnTe bandgap variation in a definite temperature range (Fig. 4).…”

Section: Methodsmentioning

confidence: 49%

Optical spectroscopy of CdTe/ZnTe quantum dot multilayers

Onishchenko

Багаев

Karczewski

et al. 2006

Phys. Status Solidi (c)

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Electronic and vibrational states in CdTe/ZnTe quantum dot multilayers grown on a thick ZnTe buffer layer are studied using optical spectroscopy methods (photoluminescence in a wide temperature range, Raman scattering, and IR reflection). It has been established that a new band appears in the Raman spectra of sample with a small ZnTe spacer layer thickness, which can be ascribed to a vibrational mode of two closely-spaced quantum dots. A comparison of results obtained under studies of structures grown on ZnTe and CdTe buffer layers shows that change of strain distribution pattern substantially modifies electron and optical spectra of QD structures. In particular, it can result in change of the band diagram type. A reason of anomalous peak position shift of quantum dot emission band is discussed.

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“…The FWHM of the high energy PL line increases as usually for QW, whereas the FWHM of the lines associated to quantum islands decrease in a oscillating way. This behaviour have been observed in quantum island of CdTe/ZnTe [4,5]. Indeed, this fact and the faster red shift of the PL maximum related to the QW peak, could be associated to the transfer of the excitons to deeper localized states in the quantum islands with increasing temperature due to the lateral migrations.…”

Section: Resultsmentioning

confidence: 79%

Quantum islands formation and optical properties of CdZnTe/ZnTe quantum wells grown by atomic layer epitaxy

Larramendi

Melo

Hernández‐Calderón

2005

Physica Status Solidi (b)

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PACS 78.55.Et, 78.67.De, 81.15.Hi In this work we report on optical properties of CdZnTe/ZnTe quantum wells (QWs) grown by atomic layer epitaxy (ALE) and the formation of quantum island during the QWs growth. The photoluminescence (PL) emission of QWs at lower temperature (250 °C) consists of two peaks. From studying the dependence of the PL integrated emission with the excitation intensity, it is found that theses both PL features have different nature. The high-energy sharp peak is associated to the excitonic recombination in the CdZnTe/ZnTe alloy quantum well while the low-energy contributions (wide peak) are assigned to the recombination in the quantum islands (compositional fluctuations with high Cd molar fraction embedded inside the active zone of the QW). The temperature dependence of the PL FWHM, energy, and intensity confirm the enhancement of the quantum efficiency of optical recombination in quantum islands. The formation of quantum islands is more likely at lower growth temperature as evidenced by the optical properties of the QWs grown at different temperatures. Since the QWs growth is following an ALE procedure (Cd -Te -Zn -Te cycles), the existence of a Cd desorption induced by Zn exposure (Cd atoms are replaced by Zn atoms) leads to the formation of the compositional fluctuations (islands) on the growing surface at lower temperatures.

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Specific features in the temperature dependence of photoluminescence from CdTe/ZnTe size-quantized islands and ultrathin quantum wells

Cited by 13 publications

References 27 publications

Free exciton emission and dephasing in individual ZnO nanowires

Free exciton emission and dephasing in individual ZnO nanowires

Optical spectroscopy of CdTe/ZnTe quantum dot multilayers

Quantum islands formation and optical properties of CdZnTe/ZnTe quantum wells grown by atomic layer epitaxy

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