Excitonic transport in ZnO

Noltemeyer, Martin; Bertram, F.; Hempel, T.; Bastek, B.; Polyakov, A. F.; Christen, J.; Brandt, M.; Lorenz, Michael; Grundmann, Marius

doi:10.1557/jmr.2012.139

Cited by 24 publications

(21 citation statements)

References 14 publications

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“…We have shown previously [1][2][3][4] that low temperature time of flight cathodolumines cence (CL) studies of exciton transport for semicon ductor samples coated with opaque masks with special geometries make it possible to obtain information about scattering mechanisms in materials; it is difficult or impossible to single them out in traditional electri cal studies of charge carrier (CC) transport. For exam ple, when analyzing the temperature dependence of the exciton mobility, it is possible to obtain more infor mation about scattering at heterojunction boundaries or sample surfaces (the influence of mechanical roughness, dipole moments, and polarization).…”

Section: Introductionmentioning

confidence: 99%

“…1 can be used effectively to study exciton trans port in direct gap semiconductor samples. Such a sample geometry was previously implemented for photoluminescence (PL) [5][6][7] and cathodolumines cence (CL) experiments [2][3][4], in which the exciton mobility in quantum wells (QWs) of materials based on gallium arsenide (PL), gallium nitride [2], and zinc oxide [3,4] (CL) were studied and mathematical models based on numerical (PL) or analytical (CL) solutions of two dimensional equations of exciton dif fusion were used.…”

Section: Introductionmentioning

confidence: 99%

“…The analysis of relations (1)- (4) shows that, in the general case, the decay of CL from a hole depends on its diameter, the exciton lifetime τ, and the diffusion coefficient of excitons D characterizing their motion under the mask. The first two quantities can be obtained directly from the experimental results.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Three-dimensional diffusion of excitons generated by an electron beam in a semiconductor material: Results of mathematical modeling

Polyakov

Stepovich

Turtin

2015

J. Synch. Investig.

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Abstact-A mathematical model of three dimensional exciton diffusion excited by a narrow electron beam in a semiconductor material is described and studied. It is shown that the obtained model can be used to esti mate the exciton diffusion coefficient in accordance with results of experimental time of flight measure ments for samples coated with an opaque mask with circular holes. Parameters that are characteristic for GaN are used in the simulation.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Three-dimensional diffusion of excitons generated by an electron beam in a semiconductor material: Results of mathematical modeling

Polyakov

Stepovich

Turtin

2015

J. Synch. Investig.

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“…At the same time, the measurements reported in this work show that transport lengths of IXs in WSQW ZnO structures reach ∼ 4 µm. In comparison, for excitons in bulk ZnO and direct excitons in ZnO structures, transport lengths are within ∼ 0.2 µm [21,22].In this work, we study polar and semipolar ZnO/MgZnO QW structures. The samples were grown by molecular beam epitaxy as in Refs.…”

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confidence: 99%

Transport of indirect excitons in ZnO quantum wells

et al. 2015

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We report on spatially-and time-resolved emission measurements and observation of transport of indirect excitons in ZnO/MgZnO wide single quantum wells.An indirect exciton (IX) in a semiconductor quantum well (QW) structure is composed of an electron and a hole confined to spatially separated QW layers. IXs were realized in wide single quantum wells (WSQW) [1][2][3][4] and in coupled quantum wells (CQW) [5][6][7][8] [2-4, 6, 7]. Their long lifetimes allow IXs to travel over large distances before recombination, providing the opportunity to study exciton transport by optical imaging [9][10][11][12][13][14][15] and explore excitonic circuit devices based on exciton transport, see [16] and references therein.Materials with a high IX binding energy allow extending the operation of the excitonic devices to high temperatures [17][18][19]. Furthermore, such materials can allow the realization of high-temperature coherent states of IXs [19]. These properties make materials with robust IXs particularly interesting. However, so far, studies of IX transport mainly concerned GaAs-based CQW. In this paper, we probe transport of IXs in ZnO/MgZnO WSQW structures. IXs in these structures are much more robust than in GaAs structures: their binding energy ∼ 30 meV [4] is considerably higher than that in GaAs/AlGaAs and GaAs/AlAs CQW (∼ 4 and ∼ 10 meV, respectively [7,20]). The binding energy of IXs is smaller than that of excitons in bulk ZnO (∼ 60 meV), however it is large enough to make the IXs stable at room temperature. At the same time, the measurements reported in this work show that transport lengths of IXs in WSQW ZnO structures reach ∼ 4 µm. In comparison, for excitons in bulk ZnO and direct excitons in ZnO structures, transport lengths are within ∼ 0.2 µm [21,22].In this work, we study polar and semipolar ZnO/MgZnO QW structures. The samples were grown by molecular beam epitaxy as in Refs. [4,23] Fig. 1a. The charges on the interfaces between ZnO and MgZnO result in a built-in electric field in the structure, which is stronger for polar samples [4,23]. The built-in electric field pulls the electron and the hole toward opposite borders of the QW, resulting in the spatial separation required for an IX.

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“…В [9][10][11]14] приведены исходные формулы, количественно описывающие двумерную диффузию частиц, генерированных электронным зондом в полупроводниковом монокристаллическом нитриде галлия для стационарного случая постоянного облучения полупроводника и нестационарного процесса, возникающего после прекращения облучения. Приведены некоторые результаты расчетов с использованием этих формул и сравнение с экспериментом с целью идентификации электрофизических параметров исследуемого полупроводникового материала.…”

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О Корректности Математических Моделей Диффузии, Обусловленной Остро Сфокусированным Электронным Зондом В Однородном Полупроводниковом Материале

Stepovich¹,

Turtin²,

Seregina³

2021

Итоги науки и техники. Серия «Современная математика и ее прило

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Проведено сравнительное исследование качественных свойств двумерной и трехмерной математических моделей диффузии частиц (неравновесных неосновных носителей заряда, экситонов), генерируемых остро сфокусированным электронным зондом в однородном полупроводниковом материале. Показано, что рассматриваемые математические модели являются математически корректными и могут быть применены для оценки электрофизических параметров однородных полупроводниковых мишеней по результатам экспериментальных измерений.

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Excitonic transport in ZnO

Abstract: Abstract

Cited by 24 publications

References 14 publications

Three-dimensional diffusion of excitons generated by an electron beam in a semiconductor material: Results of mathematical modeling

Three-dimensional diffusion of excitons generated by an electron beam in a semiconductor material: Results of mathematical modeling

Transport of indirect excitons in ZnO quantum wells

О Корректности Математических Моделей Диффузии, Обусловленной Остро Сфокусированным Электронным Зондом В Однородном Полупроводниковом Материале

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