Complex behavior of biexcitons in GaN quantum dots due to a giant built-in polarization field

Simeonov, D.; Dussaigne, Amélie; Butté, R.; Grandjean, N.

doi:10.1103/physrevb.77.075306

Cited by 67 publications

(69 citation statements)

References 26 publications

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“…19 It should be noted that in the case of crystal phase quantum heterostructures, the lineshape is well reproduced with a Lorentzian fit contrary to what is observed in GaN/AlN single quantum dots, where the lineshape is mainly Gaussian due to the spectral diffusion. 20 The power dependence of the luminescence peaks is exemplified in Fig.…”

Section: à2mentioning

confidence: 55%

Optical properties of wurtzite/zinc-blende heterostructures in GaN nanowires

Jacopin

Rigutti

Largeau

et al. 2011

Journal of Applied Physics

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The optical and structural properties of wurtzite GaN nanowires containing zinc-blende GaN inclusions of different thicknesses are investigated. Micro-photoluminescence spectra of single nanowires exhibit a series of narrow emission peaks with linewidth as low as 0.8 meV in the interval 3.1-3.42 eV. The peak energy blue-shifts with increasing excitation power following a $I 1/3 law due to the progressive band filling and to the screening of the internal field. The quantum confinement in these type-II crystal phase heterostructures was simulated in the framework of a one-dimensional effective mass model, accounting for the internal electrical polarization of the wurtzite GaN. The predicted transition energies are in good agreement with the energy statistics realized on more than 30 single nanowire emission spectra.

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Section: à2mentioning

confidence: 55%

Optical properties of wurtzite/zinc-blende heterostructures in GaN nanowires

Jacopin

Rigutti

Largeau

et al. 2011

Journal of Applied Physics

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“…The biexciton emission is different from exciton emission by its binding energy, which is typically negative in InGaN QDs due to the repulsive exciton-exciton Coulomb interaction between the two excitons [11,[19][20][21][22][23][24][25][26]. This effectively leads to a lowering of the potential barrier for a biexciton by its binding energy, which can be extracted from the overall spectral linewidth, as explained in Sec.…”

Section: Principles Of Carrier Dynamicsmentioning

confidence: 99%

Carrier dynamics in site- and structure-controlled InGaN/GaN quantum dots

et al. 2014

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We report on the carrier dynamics in InGaN/GaN dot-in-nanowire quantum dots revealed by systematic mapping between optical properties and structural parameters of the quantum dots. Such a study is made possible by using quantum dots with precisely controlled locations and sizes. We show that the carrier dynamics is governed by two competing mechanisms: 1) excitons are protected from surface recombination by a potential barrier formed due to strain-relaxation at the sidewall surface; 2) excitons can overcome the potential barrier by tunnelling and thermal activation. This carrier dynamics model successfully explains the following surprising experimental findings on individual quantum dots. Firstly, there exist strong statistical correlations among multiple optical properties of many individual quantum dots, despite variations of these properties resulting from inevitable structural variations among the quantum dots. Secondly, the antibunching property of quantum dot emission exhibits abnormal ladle-shaped dependence on the decay time and temperature. Our results can guide the way toward nitride-based high temperature singlephoton emitters and nano-photonic devices.

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“…First of all, the confined excitonic complexes are not anymore primarily bound together by Coulomb interaction; their possible dissociation is prevented by the surrounding confinement potential 13 . As a result, a large number of excitonic and charged excitonic complexes can easily form, almost regardless of the binding energies between the component particles 14,15 . Only for QDs in the strong confinement regime [16][17][18] , a biexciton (XX) in its ground state consists of two electrons and two holes occupying the lowest electron and hole orbitals, each with paired spins.…”

mentioning

confidence: 99%

Manifestation of unconventional biexciton states in quantum dots

et al. 2014

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Although semiconductor excitons consist of a fermionic subsystem (electron and hole), they carry an integer net spin similar to Cooper-electron-pairs. While the latter cause superconductivity by forming a Bose-Einstein-condensate, excitonic condensation is impeded by, for example, a fast radiative decay of the electron-hole pairs. Here, we investigate the behaviour of two electron-hole pairs in a quantum dot with wurtzite crystal structure evoking a charge carrier separation on the basis of large spontaneous and piezoelectric polarizations, thus reducing carrier overlap and consequently decay probabilities. As a direct consequence, we find a hybrid-biexciton complex with a water molecule-like charge distribution enabling anomalous spin configurations. In contrast to the conventional-biexciton complex with a net spin of s ¼ 0, the hybrid-biexciton exhibits s ¼ ± 3, leading to completely different photoluminescence signatures in addition to drastically enhanced charge carrier-binding energies. Consequently, the biexcitonic cascade via the dark exciton can be enhanced on the rise of temperature as approved by photon cross-correlation measurements.

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Complex behavior of biexcitons in GaN quantum dots due to a giant built-in polarization field

Cited by 67 publications

References 26 publications

Optical properties of wurtzite/zinc-blende heterostructures in GaN nanowires

Optical properties of wurtzite/zinc-blende heterostructures in GaN nanowires

Carrier dynamics in site- and structure-controlled InGaN/GaN quantum dots

Manifestation of unconventional biexciton states in quantum dots

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