Thermodynamics of biexcitons in a GaAs quantum well

Kim, J. C.; Wake, D. R.; Wolfe, J. P.

doi:10.1103/physrevb.50.15099

Cited by 122 publications

(118 citation statements)

References 16 publications

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“…6.8(b) shows the exciton peak area has a linear dependence on the excitation power, whereas the biexciton peak area increases quadratically before saturation. This power-dependence of the biexciton is in good agreement with an early work on the thermodynamic evaluation of exciton and biexciton populations [134].…”

Section: 5supporting

confidence: 74%

Polarized Optical Two-dimensional Fourier Transform Spectroscopy of Semiconductors

Zhang¹,

Li²,

Cundiff³

et al. 2006

15th International Conference on Ultrafast Phenomena

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Section: 5supporting

confidence: 74%

Polarized Optical Two-dimensional Fourier Transform Spectroscopy of Semiconductors

Zhang¹,

Li²,

Cundiff³

et al. 2006

15th International Conference on Ultrafast Phenomena

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“…These systems show nontrivial Coulomb correlation effects leading to interesting optical and transport characteristics not seen in bulk materials. A strong increase of the binding energy of the excitonic complexes was found experimentally [1,2,3,4,5,6,7,8,9,10] with decreasing quantum well (QW) width and increasing magnetic field [11].…”

Section: Introductionmentioning

confidence: 99%

“…Quasi-two-dimensional systems like GaAs QW's have been extensively investigated in the last years, both experimentally [1,2,4,5,6,7,8,9,10] and theoretically [12,13,14,15,16].…”

Section: Numerical Simulation Approachmentioning

confidence: 99%

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Influence of well-width fluctuations on the binding energy of excitons, charged excitons, and biexcitons inGaAs-based quantum wells

et al. 2004

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We present a first-principle path integral Monte-Carlo (PIMC) study of the binding energy of excitons, trions (positively and negatively charged excitons) and biexcitons bound to single-island interface defects in quasi-two-dimensional GaAs/Al x Ga 1−x As quantum wells. We discuss in detail the dependence of the binding energy on the size of the well width fluctuations and on the quantum-well width. The numerical results for the well width dependence of the exciton, trions and biexciton binding energy are in good quantitative agreement with the available experimental data.

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“…The emission strength of the XX/D peak at different excitation densities is also depicted in the 3D plot of Figure (S1). At thermal equilibrium (ignoring possible temperature increase at elevated excitation densities), we would expect a quadratic relation between the biexciton PL integrated intensity and the excitation power density 30 , that is IPL  Pex 2 . However, exponents of 1.2-1.9 are commonly observed in quantum-well systems and attributed to the lack of equilibrium between the states 31 , as well as to the kinetics of biexciton formation and exciton recombination 26 .…”

mentioning

confidence: 99%

Room temperature observation of biexcitons in exfoliated WS2 monolayers

Paradisanos

Germanis

Pelekanos

et al. 2017

Applied Physics Letters

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Single layers of WS2 are direct gap semiconductors with high photoluminescence (PL) yield holding great promise for emerging applications in optoelectronics. The spatial confinement in a 2D monolayer together with the weak dielectric screening lead to huge binding energies for the neutral excitons as well as other excitonic complexes, such as trions and biexcitons whose binding energies scale accordingly. Here, we report on the existence of biexcitons in mechanically exfoliated WS2 flakes from 78 K up to room temperature. Performing temperature and power dependent PL measurements, we identify the biexciton emission channel through the superlinear behavior of the integrated PL intensity as a function of the excitation power density. On the contrary, neutral and charged excitons show a linear to sublinear dependence in the whole temperature range. From the energy difference between the emission channels of the biexciton and neutral exciton, a biexciton binding energy of 65-70 meV is determined. *Corresponding authors: gnk@materials.uoc.gr ; stratak@iesl.forth.gr 2 The interest on two-dimensional (2D) materials has been steadily increasing since the discovery of graphene, a material with fascinating properties and great potential for various applications 1 . Transition metal dichalcogenides (TMDs) with the form MX2 (M = Mo, W, Ti, etc and X = S, Se, Te) exhibit a structure very similar to that of graphene and have attracted significant attention of the scientific community 2-5 for a number of reasons. Among the most attractive features of TMD compounds is that their electronic properties can vary from metallic to those of a wide band gap semiconductor depending on the structure, composition and dimensionality, while their band structure can be easily tuned by applying stress 6 . Owing to such layer-dependent electronic structure, TMDs exhibit extraordinary optoelectronic properties 7,8 as well as potential for enhanced performance in applications such as photodetectors 9 , photovoltaics 10,11 and non-linear optical components 12 .Among their prominent optical properties, TMD monolayers show strong PL in the visible and near-infrared spectral range, due to the transition from indirect band gap semiconductors in their bulk and few-layer forms, to direct band gap semiconductors in the monolayer limit 13 . Besides this, the spatial confinement of carriers in a 2D monolayer lattice and the weak dielectric screening, give rise to unusually strong excitonic effects and high binding energies [14][15][16] . These properties favor the stability of a variety of excitonic quasiparticles with extremely large binding energies, including neutral excitons with binding energies of several hundred meV 17,18 , charged excitons (trions) was shown that the biexciton emission in WS2 can be electrically tuned 27 , which is of great importance for TMDs-based photonic devices.The unusually strong excitonic effects in TMDs strongly suggest an enhanced thermal stability of biexciton emission. While neutral and charged excitons have...

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Thermodynamics of biexcitons in a GaAs quantum well

Cited by 122 publications

References 16 publications

Polarized Optical Two-dimensional Fourier Transform Spectroscopy of Semiconductors

Polarized Optical Two-dimensional Fourier Transform Spectroscopy of Semiconductors

Influence of well-width fluctuations on the binding energy of excitons, charged excitons, and biexcitons inGaAs-based quantum wells

Room temperature observation of biexcitons in exfoliated WS2 monolayers

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