First-principles study of oxygen and aluminum defects in β-Si3N4: Compensation and charge trapping

Grillo, Maria Elena; Elliott, Simon D.; Rodríguez, Jesús; Áñez, Rafael; Coll, David S.; Suhane, A.; Breuil, L.; Arreghini, A.; Degraeve, R.; Shariq, A.; Beyer, V.; Czernohorsky, M.

doi:10.1016/j.commatsci.2013.07.048

Cited by 14 publications

(8 citation statements)

References 28 publications

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“…Various candidates for defect energy levels in β-Si 3 N 4 and β-SiAlON have been reported [15,16,20,[23][24][25][26][27]. The band gap energies between the valence band (VB) and conduction band (CB) have been reported to be 5.0-5.3 eV.…”

Section: Blue Emission and Nitrogen Vacancymentioning

confidence: 99%

Luminescence and afterglow due to defects in β-SiAlON crystal powder

Suda

Kamigaki

Miyagawa

et al. 2020

J. Phys. D: Appl. Phys.

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Si6−zAlzOzN8−z (β-SiAlON):Eu2+ is among the most suitable green phosphors for white LEDs. To further improve the performance of this phosphor, it is important to investigate the properties of the nitride host crystal, β-SiAlON, which is considered to contain nitrogen vacancy defects (VN) to some extent. From time-resolved fluorescence (TR-F) measurements of β-SiAlON without luminescent activators, we observed blue, yellow, and ultraviolet emissions. We focused on the blue emission typically centered at 460 nm, which was quenched at room temperature, but showed a continued afterglow for several milliseconds. The electron spin resonance signal of Si dangling bonds due to VN in β-SiAlON was observed to have a high concentration of 5.8 × 1016 g−1. We have previously reported the blue emission in nitride phosphor CaAlSiN3:Eu2+, for which the origin has been identified as VN. Therefore, we predicted that the blue afterglow might cause the green emission of the Eu2+ ions to continue for several milliseconds in β-SiAlON:Eu2+. In this study, we proved that spectra decay characteristics measured by TR-F are useful for clarifying the phosphor characteristics interacting with the defects of β-SiAlON, such as VN.

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Section: Blue Emission and Nitrogen Vacancymentioning

confidence: 99%

Luminescence and afterglow due to defects in β-SiAlON crystal powder

Suda

Kamigaki

Miyagawa

et al. 2020

J. Phys. D: Appl. Phys.

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“…(i) Eu = 0, defect and afterglow: nitrogen vacancy (V N ) defects models, as for β-SiAlON or β-Si 3 N 4 , have been proposed [19,20,26,[31][32][33], as shown in figure 13(b). This V N is composed of three Si-DBs, and it behaves as a trap center for electrons or holes.…”

Section: Tl and Energy Levels Of Defectsmentioning

confidence: 99%

Effects of Eu²⁺ on the luminescence and afterglow that arise from defects in β-SiAlON:Eu²⁺

Suda¹,

Kamigaki²,

Miyagawa³

et al. 2020

J. Phys. D: Appl. Phys.

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Si6−z Al z O z N8−z (β-SiAlON):Eu2+ is known as a high brightness green phosphor. When β-SiAlON:Eu2+ is excited with UV light (approximately 265 nm), a curved decay afterglow is observed as a result of the trap levels created by the defects in the host crystal. However, the defect signals are hardly detected by electron spin resonance (ESR) and thermoluminescence (TL), which are common defect detection methods. Non-doped (Eu = 0) β-SiAlON emits blue light from a nitrogen defect, and the defect can be detected by time-resolved fluorescence (TR-F) measurement at 15 K. Similarly, upon measuring TR-F at 15 K for Eu-doped β-SiAlON, a blue emission (460 nm) is detected in addition to the green emission of Eu2+ (530 nm). The green emission has an afterglow of several milliseconds that decays with the same decay curve as the blue emission of the defect, and its time constant is 5–6 ms. This blue emission is quenched by the Eu concentration and temperature. The Si dangling bond signal intensity, observed by ESR, and the glow intensity, observed by TL, also decrease with the increment of the Eu concentration. It is difficult to detect the defect as an electron trap owing to the interaction between Eu2+ and the nitrogen defect. However, the afterglow arising from the electrons trapped at the defect level does not decrease with the Eu concentration. The blue emission was quenched at room temperature but the afterglow was not reduced, which also affected the light emission above room temperature. Therefore, it is possible to detect nitrogen defects optically by TR-F at low temperature, as well as the Eu2+ afterglow of several milliseconds.

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“…While, the N‐rich condition means that

μ_{N}

is taken as the energy per atom of the N 2 molecule, and

μ_{Si} = \frac{1}{3} (μ_{{normalSi}_{3} {normalN}_{4}} - 4 μ_{normalN})

. In addition, for the chemical potentials of impurities,

μ_{O}

are given by the stability limit of

α

‐quartz phase of silica (

α

‐SiO 2 ) () and

μ_{Al}

is taken as the energy per atom of crystalline fcc Al.…”

Section: Calculation Proceduresmentioning

confidence: 99%

“…studies the impact of hydrogen in Si 3 N 4 layer on the MONOS‐type memory during P/E cycles . Post deposition annealing causes aluminum (Al) and oxygen (O) impurities diffusion into SiN trap layer in typical TANOS memory (). And Ref.…”

Section: Introductionmentioning

confidence: 99%

Impact of native defects and impurities in m−HfO₂ and β−Si₃N₄ on charge trapping memory devices: A first principle hybrid functional study

Dai

Wang

et al. 2016

Physica Status Solidi (b)

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Using hybrid density functional calculations, this paper systematically investigated the common defects in m‐HfO2 and β‐Si3N4 trapping layer, respectively, on the performance of charge trapping memory (CTM) devices. Defects may act as charge traps or fixed charges, however, only traps can be used to store charges. Thus, firstly, the paper distinguished traps or fixed charges of defects in trapping layer through the band alignment method. Then we can restrain the formation of defects that act as fixed charges in manufacturing CTM devices, which is very meaningful in improving the performance of CTM. Secondly, it studied the storage performance of traps in m‐HfO2 and β‐Si3N4 by analyzing the formation energy, the atomistic structural change during program/erase (P/E) cycles, and localization energy. The simulation results found that only some defects can be charge traps in m‐HfO2 and β‐Si3N4, and the charge transition of these traps only appeared between certain charged states. In addition, these traps show reversible structural change during P/E cycles and different localizing abilities for holes and electrons. Therefore, this study would provide some theoretical guidance for improving the performance of CTM.

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First-principles study of oxygen and aluminum defects in β-Si3N4: Compensation and charge trapping

Cited by 14 publications

References 28 publications

Luminescence and afterglow due to defects in β-SiAlON crystal powder

Luminescence and afterglow due to defects in β-SiAlON crystal powder

Effects of Eu²⁺ on the luminescence and afterglow that arise from defects in β-SiAlON:Eu²⁺

Impact of native defects and impurities in m−HfO₂ and β−Si₃N₄ on charge trapping memory devices: A first principle hybrid functional study

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First-principles study of oxygen and aluminum defects in β-Si3N4: Compensation and charge trapping

Cited by 14 publications

References 28 publications

Luminescence and afterglow due to defects in β-SiAlON crystal powder

Luminescence and afterglow due to defects in β-SiAlON crystal powder

Effects of Eu2+ on the luminescence and afterglow that arise from defects in β-SiAlON:Eu2+

Impact of native defects and impurities in m−HfO2 and β−Si3N4 on charge trapping memory devices: A first principle hybrid functional study

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Product

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Effects of Eu²⁺ on the luminescence and afterglow that arise from defects in β-SiAlON:Eu²⁺

Impact of native defects and impurities in m−HfO₂ and β−Si₃N₄ on charge trapping memory devices: A first principle hybrid functional study