Photoluminescence of Ta2O5 films formed by the molecular layer deposition method

Baraban, A. P.; Дмитриев, В. А.; Prokof'ev, V. A.; Дрозд, В. Е.; Filatova, E. O.

doi:10.1134/s1063785016040040

Cited by 6 publications

(3 citation statements)

References 4 publications

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“…A maximum intensity of the 2.75 eV blue luminescence band was observed under the excitation with 4.45 eV quanta. A similar result (2.8 eV PL peak and the 4.5 eV PLE peak) was previously obtained for the tantalum oxide synthesized by the molecular layer deposition method by using the Xe lamp as the photon excitation source . Within the experimental accuracy, the blue luminescence excitation peak for our samples has the same energy as the 4.55 eV optical absorption peak (Figure a) and it is close to the possible optical transitions with energies of 4.50 and 4.65 eV that are predicted from the quantum-chemical calculations (Figure b).…”

Section: Resultssupporting

confidence: 87%

Charge Transport and the Nature of Traps in Oxygen Deficient Tantalum Oxide

Gritsenko

Перевалов

Voronkovskii

et al. 2018

ACS Appl. Mater. Interfaces

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Optical and transport properties of nonstoichiometric tantalum oxide thin films grown by ion beam deposition were investigated in order to understand the dominant charge transport mechanisms and reveal the nature of traps. The TaO films composition was analyzed by X-ray photoelectron spectroscopy and by quantum-chemistry simulation. From the optical absorption and photoluminescence measurements and density functional theory simulations, it was concluded that the 2.75 eV blue luminescence excited in a TaO by 4.45 eV photons, originates from oxygen vacancies. These vacancies are also responsible for TaO conductivity. The thermal trap energy of 0.85 eV determined from the transport experiments coincides with the half of the Stokes shift of the blue luminescence band. It is argued that the dominant charge transport mechanism in TaO films is phonon-assisted tunneling between the traps.

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Section: Resultssupporting

confidence: 87%

Charge Transport and the Nature of Traps in Oxygen Deficient Tantalum Oxide

Gritsenko

Перевалов

Voronkovskii

et al. 2018

ACS Appl. Mater. Interfaces

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“…To explain this feature, it is necessary to recall that earlier PL studies of Ta 2 O 5 layers on silicon (Baraban et al 2016) showed the presence of localized energy levels in the Ta 2 O 5 band gap, which are inherent in luminescence centers. The PL was excited due to the band-band generation of electron-hole pairs and/ or the transfer of an electron from the valence band of Ta 2 O 5 to the LC energy level in the forbidden band.…”

Section: Luminescence Of Ta 2 O 5 Layer Excited By Electrons (Cl and El)mentioning

confidence: 99%

Luminescence of insulator layers on silicon excited by electrons

Baraban

Дмитриев

2021

Physics of Complex Systems

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We present a comparative analysis of cathodoluminescence (CL) and electroluminescence (EL) spectra measured on Si-SiO 2 and Si-Ta 2 O 5 structures with various thicknesses of insulator layers. Spectral distribution of luminescence depends on how the insulator layer was formed, its thickness and type of excitation. The analysis indicates that CL and EL spectra of Si-SiO 2 structures, grown by thermal oxidation of silicon in "dry" oxygen, are almost identical in spectral composition. Based on the dependence of intensity of the luminescence band with a maximum at energy of 2.2 eV, it was concluded that the corresponding luminescence centers are uniformly distributed over the oxide layer thickness in the range of 30-200 nm. It is assumed that these luminescence centers are oxygen vacancies formed during the thermal oxidation of silicon. In the case of Ta 2 O 5 layers on silicon, the presence of defects (luminescence centers) in the oxide layer leads to the formation of a set of energy levels in the band gap of the Ta 2 O 5 layers obtained by ALD. They appear in the luminescence spectra regardless of the excitation method.

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“…Цель настоящей работы заключалась в выявлении особенностей электронного строения слоя Та 2 О 5 и области межфазовой границы SiO 2 −Та 2 О 5 , формируемой в процессе нанесения второго диэлектрического слоя путем использования метода электролюминесценции (ЭЛ) и привлечения результатов [6,7], полученных нами ранее с использованием методов катодолюминесценции (КЛ) и фотолюминесценции (ФЛ).…”

Section: Introductionunclassified

Электролюминесценция слоев Ta-=SUB=-2-=/SUB=-O-=SUB=-5-=/SUB=-, полученных методом молекулярного наслаивания

Baraban¹,

Дмитриев²,

Дрозд³

et al. 2020

Журнал Технической Физики

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Abstract. The work shows the possibility of using electroluminescence to study the structures of Si-Ta2O5 and Si-SiO2-Ta2O5 and to obtain the information about the electronic structure of the Ta2O5 layer and the properties of the SiO2-Ta2O5 boundary. A model of the electronic structure of the Ta2O5 layer obtained by molecular layering (atomic layer deposition) is proposed to explain the type of spectral distribution of luminescence regardless of the method of its excitation. It is shown that the formation of a Ta2O5 layer on the surface of thermally oxidized silicon is accompanied by transformation of the near-surface region of SiO2 and quenching of the luminescence band in the spectral region of 650 nm.

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Photoluminescence of Ta2O5 films formed by the molecular layer deposition method

Cited by 6 publications

References 4 publications

Charge Transport and the Nature of Traps in Oxygen Deficient Tantalum Oxide

Charge Transport and the Nature of Traps in Oxygen Deficient Tantalum Oxide

Luminescence of insulator layers on silicon excited by electrons

Электролюминесценция слоев Ta-=SUB=-2-=/SUB=-O-=SUB=-5-=/SUB=-, полученных методом молекулярного наслаивания

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