Many-body effects on excitons properties in GaN/AlGaN quantum wells

Traetta, G.; Cingolani, R.; Carlo, Aldo Di; Sala, Fabio Della; Lugli, Paolo

doi:10.1063/1.125932

Cited by 27 publications

(15 citation statements)

References 19 publications

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“…and here is reduced by a factor of 0.63 to account for a reduced dipole moment in GaN due to the internal electric field in the heterostructure [14]. The exciton Bohr radius in the QW is approximated at 3 nm [15], and the translational mass of an exciton is taken as the sum of the effective masses of the electron (m e ¼ 0:2m 0 ) and hole (m h ¼ 1:3m 0 ), where m 0 is the free electron mass [13].…”

mentioning

confidence: 99%

Dependence of Resonance Energy Transfer on Exciton Dimensionality

et al. 2011

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mentioning

confidence: 99%

Dependence of Resonance Energy Transfer on Exciton Dimensionality

et al. 2011

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“…This causes a strong reduction of the exciton binding energy and of the absorption coefficient, as predicted in Ref. 18, thus modifying the electric-field induced and the many-body nonlinearities of GaN OW's.…”

Section: Theory and Comparison With The Experimentsmentioning

confidence: 69%

Mesoscopic-capacitor effect inGaN/AlxGa<

et al. 2001

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We show that wide GaN quantum wells behave like mesoscopic capacitors. The electron-hole pairs are separated by the spontaneous and piezoelectric polarization fields and accumulated in the well, resulting in a well-width dependent screening of the built-in field. The extent to which such screening is effective depends on the interplay between radiative and nonradiative recombination probabilities, which deplete the ground level of the quantum well, causing the recovery of the unscreened built-in field. The account of the mesoscopic capacitor effect provides a quantitative description of the optical spectra and of the time dynamics of a set of high quality quantum wells with well characterized structural parameters.

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“…The obtained band-to band transition energies are shown in Fig. 1 after subtracting the corresponding values of excitonic binding energies taken from [12]. Then in similar way we calculate the fundamental transition energies for each quantum well for increasing value of hydrostatic pressure from 0 to 10 GPa.…”

Section: Resultsmentioning

confidence: 99%

“…Only the emission from the narrow quantum wells(4,6,8,10 MLs) belongs to this category. The lines related to12, 16, 24, 32 …”

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confidence: 99%

Large Built-in Electric Field and Its Influence on the Pressure Behavior of the Light Emission from GaN/AlGaN Strained Quantum Wells

Perlin

Suski

Łepkowski

et al. 2001

phys. stat. sol. (a)

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Influence of hydrostatic pressure on the light emission from strained GaN/AlGaN multi-quantumwell systems has been studied. Pressure coefficients of the photoluminescence peak energies show a strong reduction with respect to that of the GaN energy gap and this reduction is a function of the quantum-well thickness. The decrease of the light emission pressure coefficient may be almost 40% for a 32 monolayer (8 nm) thick quantum well in comparison with a 4 monolayer well. We explain this effect by a hydrostatic-pressure-induced increase of the piezoelectric field in the GaN/ AlGaN quantum structures.Introduction The contribution of the built-in electric field to the properties of wurtzite group-III nitrides has been widely disputed during the last few years [1-3]. Concerning experimental observations, the Quantum Confined Stark Effect (QCSE) and related peculiarities in the light emission from InGaN/GaN quantum wells (QWs) as well as high concentration carrier gases at undoped GaN/AlGaN heterostructures have been demonstrated. Spontaneous polarization and a huge piezoelectric field due to the large lattice/thermal expansion mismatch of the different nitride binary compounds lead to built-in electric fields, which can achieve a magnitude of few MV/cm.Another puzzling behavior of InGaN/GaN QWs consists in findings of anomalously low pressure coefficients of the photo-and electro-luminescence lines (dE/dp) [4]. dE/dp shows a dramatic decrease, which scales well with the decrease of E in variety of InGaN/GaN quantum structures. Since such a behavior suggests involvement of strongly localized states, it was tempting to associate it with In segregation in the InGaN QW. Such segregation results in narrowing of the InGaN alloy bandgap [5]. Accordingly, regions of high In content produce highly efficient radiative recombination which occurs due to strong localization of excitons/electron-hole pairs. However strong arguments against this interpretation have been supplied by Vaschenko et al. [6] who reported on the pressure induced increase of the photoluminescence decay time, t, in QWs of InGaN/GaN. This effect corresponds to the spatial separation of the wave functions of recombining electron and hole pairs due to the increase of a strong electric field (QCSE) in the studied structures. Moreover, a significant decrease of dE/dp accompanying the increase of t has been also found.

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Many-body effects on excitons properties in GaN/AlGaN quantum wells

Cited by 27 publications

References 19 publications

Dependence of Resonance Energy Transfer on Exciton Dimensionality

Dependence of Resonance Energy Transfer on Exciton Dimensionality

Mesoscopic-capacitor effect inGaN/AlxGa<

Large Built-in Electric Field and Its Influence on the Pressure Behavior of the Light Emission from GaN/AlGaN Strained Quantum Wells

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