Quantitative description of disorder parameters in (GaIn)(NAs) quantum wells from the temperature-dependent photoluminescence spectroscopy

Rubel, Oleg; Galluppi, M.; Baranovskiǐ, S. D.; Volz, Kerstin; Geelhaar, Lutz; Riechert, H.; Thomas, P.; Stolz, W.

doi:10.1063/1.2058192

Cited by 85 publications

(119 citation statements)

References 28 publications

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“…Previously, smaller reductions in the GaAs band gap were achieved in dilute nitrides, where nitrogen was incorporated at the As sites [11][12][13][14][15][16] . In that case the E g reduction was understood as the hybridization (anticrossing) of unoccupied nitrogen s orbitals with the host conduction band 17,18 , giving localized states responsible for the conduction band tail detected experimentally.…”

Section: Introductionmentioning

confidence: 99%

Configuration dependence of band-gap narrowing and localization in diluteGaAs1−xBixalloys

et al. 2016

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Anion substitution with bismuth (Bi) in III-V semiconductors is an effective method for experimental engineering of the band gap Eg at low Bi concentrations (≤ 2%), in particular in gallium arsenide (GaAs). The inverse Bi-concentration dependence of Eg has been found to be linear at low concentrations x and dominated by a valence band-defect level anticrossing between As and Bi occupied p levels. Predictive models for the valence band hybridization require a first-principle understanding which can be obtained by density functional theory with the main challenges being the proper description of Eg and the spin-orbit coupling. By using an efficient method to include these effects, it is shown here that at high concentrations Eg is modified mainly by a Bi-Bi p orbital interaction and by the large Bi atom-induced strain. In particular, we find that at high concentrations the Bi-Bi interactions depend strongly on model periodic cluster configurations, which is not captured by tight-binding models. Averaging over various configurations supports the defect level broadening picture. This points to the role of different atomic configurations obtained by varying the experimental growth conditions in engineering arsenide band gaps, in particular for telecommunication laser technology.

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Section: Introductionmentioning

confidence: 99%

Configuration dependence of band-gap narrowing and localization in diluteGaAs1−xBixalloys

et al. 2016

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“…We assume that the defect density is correlated with the spectral shift between exciton resonances measured in PL and absorption, known as the SS. As a simple method based entirely on commonly used linear optical spectroscopy methods, SS has been used to characterize a wide variety of systems [19,35] including defect density [36][37][38] and thickness fluctuations in quantum wells [20,39,40] and size distribution in ensembles of quantum dots [41,42].…”

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confidence: 99%

Disorder-dependent valley properties in monolayer WSe2

et al. 2017

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We investigate the effect of disorder on exciton valley polarization and valley coherence in monolayer WSe 2 . By analyzing polarization properties of photoluminescence, the valley coherence (VC) and valley polarization (VP) is quantified across the inhomogeneously broadened exciton resonance. We find that disorder plays a critical role in the exciton VC, while affecting VP less. For different monolayer samples with disorder characterized by their Stokes Shift (SS), VC decreases in samples with higher SS while VP does not follow a simple trend. These two methods consistently demonstrate that VC as defined by the degree of linearly polarized photoluminescence is more sensitive to disorder, motivating further theoretical studies.

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“…5, the PL spectra broaden due to thermalisation of carriers across the range of localised states. 29,[45][46][47][50][51][52] Over this temperature range, the decay times at the PL peak and on the low energy side of the spectra remain constant $11(61) ns, while the decay times on the high energy side of the spectra increase progressively with increasing temperature, such that at 300 K the decay time is essentially constant across the spectrum. This suppression of the spectral dependence of the PL decay time with increasing temperature has been reported by several groups.…”

Section: -4mentioning

confidence: 94%

A comparison of the optical properties of InGaN/GaN multiple quantum well structures grown with and without Si-doped InGaN prelayers

Davies

Hammersley

Massabuau

et al. 2016

Journal of Applied Physics

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In this paper, we report on a detailed spectroscopic study of the optical properties of InGaN/GaN multiple quantum well structures, both with and without a Si-doped InGaN prelayer. In photoluminescence and photoluminescence excitation spectroscopy, a 2nd emission band, occurring at a higher energy, was identified in the spectrum of the multiple quantum well structure containing the InGaN prelayer, originating from the first quantum well in the stack. Band structure calculations revealed that a reduction in the resultant electric field occurred in the quantum well immediately adjacent to the InGaN prelayer, therefore leading to a reduction in the strength of the quantum confined Stark effect in this quantum well. The partial suppression of the quantum confined Stark effect in this quantum well led to a modified (higher) emission energy and increased radiative recombination rate. Therefore, we ascribed the origin of the high energy emission band to recombination from the 1st quantum well in the structure. Study of the temperature dependent recombination dynamics of both samples showed that the decay time measured across the spectrum was strongly influenced by the 1st quantum well in the stack (in the sample containing the prelayer) leading to a shorter average room temperature lifetime in this sample. The room temperature internal quantum efficiency of the prelayer containing sample was found to be higher than the reference sample (36% compared to 25%) which was thus attributed to the faster radiative recombination rate of the 1st quantum well providing a recombination pathway that is more competitive with nonradiative recombination processes.

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Quantitative description of disorder parameters in (GaIn)(NAs) quantum wells from the temperature-dependent photoluminescence spectroscopy

Cited by 85 publications

References 28 publications

Configuration dependence of band-gap narrowing and localization in diluteGaAs1−xBixalloys

Configuration dependence of band-gap narrowing and localization in diluteGaAs1−xBixalloys

Disorder-dependent valley properties in monolayer WSe2

A comparison of the optical properties of InGaN/GaN multiple quantum well structures grown with and without Si-doped InGaN prelayers

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