Temperature dependence of the band gap energy of crystalline CdTe

Fonthal, Gerardo; Tirado-Mejı́a, L.; Marin-Hurtado, Jorge I.; Calderón, Hernando Ariza; Mendoza-Álvarez, J.G.

doi:10.1016/s0022-3697(99)00254-1

Cited by 111 publications

(61 citation statements)

References 33 publications

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“…The data from this low-nanocrystal-concentration region of the dried drop are consistent with a temperature increase of at most 10 K above room temperature [41,42]. This is in fact the maximal expected thermal effect of a focused laser for the powers and spot size used in our experiments, given dissipation through contact with the Si 3 N 4 substrate which we suppose remains at room temperature for regions more than 5 μm away from the laser spot.…”

Section: Resultssupporting

confidence: 83%

Characterization of the Dynamics of Photoluminescence Degradation in Aqueous CdTe/CdS Core-Shell Quantum Dots

Assis

et al. 2015

J Fluoresc

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We investigate the effects of the excitation power on the photoluminescence spectra of aqueous CdTe/CdS core-shell quantum dots. We have focused our efforts on nanoparticles that are drop-cast on a silicon nitride substrate and dried out. Under such conditions, the emission intensity of these nanocrystals decreases exponentially and the emission center wavelength shifts with the time under laser excitation, displaying a behavior that depends on the excitation power. In the low-power regime a blueshift occurs, which we attribute to photo-oxidation of the quantum dot core. The blueshift can be suppressed by performing the measurements in a nitrogen atmosphere. Under high-power excitation the nanoparticles thermally expand and aggregate, and a transition to a redshift regime is then observed in the photoluminescence spectra. No spectral changes are observed for nanocrystals dispersed in the solvent. Our results show a procedure that can be used to determine the optimal conditions for the use of a given set of colloidal quantum dots as light emitters for photonic crystal optical cavities.

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Section: Resultssupporting

confidence: 83%

Characterization of the Dynamics of Photoluminescence Degradation in Aqueous CdTe/CdS Core-Shell Quantum Dots

Assis

et al. 2015

J Fluoresc

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“…The energy variation with temperature induced by the TE, considering α th (T = 300K), is linear and decreases in all the temperatures range. The approach that considers a constant value α th (T = 300K) at all temperature interval has been discussed in several papers [8,52,53]. A large difference between the two curves can be seen in almost all the temperature range, except at the T = 0K point.…”

Section: Resultsmentioning

confidence: 99%

Thermal expansion contribution to the temperature dependence of excitonic transitions in GaAs and AlGaAs

et al. 2004

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Photoluminescence and photoreflectance measurements have been used to determine excitonic transitions in the ternary AlxGa1−xAs alloy in the temperature range from 2 to 300 K. The effect of the thermal expansion contribution on the temperature dependence of excitonic transitions for different aluminum concentrations in the AlxGa1−xAs alloy is presented. Results from this study have shown that the negative thermal expansion (NTE) in the AlxGa1−xAs alloy, in the low temperature interval, induces a small blueshift in the optical transition energy. In the temperature range from ∼23 to ∼95 K there is a competition between the NTE effect and the electron-phonon interaction. Using the thermal expansion coefficient in the 2 -300 K temperature range, the thermal expansion contribution to GaAs, at room temperature, represents 21% of the total shift of the excitonic transition energy. After subtracting the thermal expansion contribution from the experimental temperature dependence of the excitonic transitions, in the AlxGa1−xAs alloy, the contribution to the electron-phonon interaction of the longitudinal optical phonon increases, relatively to the longitudinal acoustical phonon, with increasing Al concentration.

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“…63 In this section, we examine the electronic structure of the monolayer α-CdTe and compare its properties with that of zb-structure.…”

Section: Electronic Properties Of α-Cdtementioning

confidence: 99%

Stable monolayer α-phase of CdTe: strain-dependent properties

2017

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CdTe is a well known and widely used binary compound for optoelectronic applications. In this study, we propose the thinnest, free standing monolayer of CdTe which holds the tetragonalPbO (α-PbO) symmetry. The structural, electronic, vibrational and strain dependent properties are investigated by means of first principles calculations based on density functional theory. Our results demonstrate that the monolayer α-CdTe is a dynamically stable and mechanically flexible material. It is found that the thinnest monolayer crystal of CdTe is a semiconductor with a direct band gap of 1.95 eV, which corresponds to red light in the visible spectrum. Moreover, it is found that the band gap can be tunable under biaxial strain. With its strain-controllable direct band gap within the visible spectrum, stable α-phase of monolayer CdTe is a suitable candidate for optoelectronic device applications.

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Temperature dependence of the band gap energy of crystalline CdTe

Cited by 111 publications

References 33 publications

Characterization of the Dynamics of Photoluminescence Degradation in Aqueous CdTe/CdS Core-Shell Quantum Dots

Characterization of the Dynamics of Photoluminescence Degradation in Aqueous CdTe/CdS Core-Shell Quantum Dots

Thermal expansion contribution to the temperature dependence of excitonic transitions in GaAs and AlGaAs

Stable monolayer α-phase of CdTe: strain-dependent properties

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