Red-luminescence band: A tool for the quality assessment of germanium and silicon nanocrystals

Fraj, Ibtissem; Favre, Luc; David, Thomas; Abbarchi, Marco; Liu, K.; Claude, Jean-Benoît; Ronda, A.; Naffouti, Meher; Saidi, F.; Hassen, F.; Maâref, H.; Aqua, Jean Noël; Berbézier, Isabelle

doi:10.1016/j.apsusc.2017.05.025

Cited by 5 publications

(2 citation statements)

References 53 publications

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“…The electronic, transport, and optical properties of silicon (Si) and germanium (Ge) nanomaterials have been largely investigated in the past, both experimentally and theoretically, due to their promising applications in optoelectronics and photovoltaics. − Moreover, it has been shown that Si and Ge can be combined to obtain innovative materials that can be easily integrated into existing devices. Compared to pure Si and Ge materials, Si/Ge heterostructures offer more possibilities to tune the above-said properties. , This can be achieved by varying Si and Ge atom concentration and their spatial disposition, by modifying the geometry of Si/Ge interface, and by modulating both strain and the quantum confinement effect (QCE) to obtain systems with the desired properties.…”

Section: Introductionmentioning

confidence: 99%

Interplay of Quantum Confinement and Strain Effects in Type I to Type II Transition in GeSi Core–Shell Nanocrystals

et al. 2023

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The electronic properties of hydrogenated, spherical SiGe and GeSi core–shell nanocrystals, with a diameter ranging from 1.8 to 4.0 nm, are studied within density functional theory. Effects induced by quantum confinement and strain on the near-band-edge state localization, as well as the band-offset properties between Si and Ge regions, are investigated in detail. On the one hand, we prove that SiGe core–shell nanocrystals always show a type II band-offset alignment, with the HOMO mainly localized on the Ge shell region and the LUMO mainly localized on the Si core region. On the other hand, our results point out that a type II offset cannot be observed in small (diameter less than 3 nm) GeSi core–shell nanocrystals. In these systems, quantum confinement and strain drive the near-band-edge states to be mainly localized on Ge atoms, i.e., in the core region. In larger GeSi core–shell nanocrystals, instead, the formation of a type II offset can be engineered by playing with both core and shell thickness. The factors which determine the band-offset character at the Ge/Si interface are discussed in detail.

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Section: Introductionmentioning

confidence: 99%

Interplay of Quantum Confinement and Strain Effects in Type I to Type II Transition in GeSi Core–Shell Nanocrystals

et al. 2023

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“…Niquet et al [13] combined ab initio calculations with experimental data and differentiated between two emission ranges: (1) a blue-green emission, which is found to be size-independent; (2) a near-infrared emission arising from the Ge crystal, whose energy is strongly connected to the NC size. The highest PL peak energy that could be assigned to radiative recombination of quantum-confined excitons in Ge was in the red spectral region, for particle sizes of 1 nm [7,[14][15][16]. For higher emission energies, ultra-small NCs (diameter<1 nm) are required.…”

Section: Introductionmentioning

confidence: 99%

Role of surface passivation on visible and infrared emission of Ge quantum dots formed by dewetting

et al. 2019

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The dual action of oxide-related defects in the visible and infrared emission of germanium (Ge) self-assembled quantum dots (QDs) is discussed. The Ge particles were fabricated by solid-state dewetting on a thin layer of SiO 2. Subsequent surface passivation by amorphous silicon was carried out for several samples. All samples were encapsulated by SiO 2. Atomic force microscopy analysis indicates a linear relationship between the size of QDs and the initial thickness of the amorphous Ge films. The crystallization of the QDs was evidenced by transmission electron microscopy and Raman spectroscopy. Photoluminescence measurements show that the main visible emission is blue-green centred around 520 nm. The luminescence attributed to the radiative recombination of quantum-confined excitons is only observed when the surface is in-situ passivated prior to the deposition of the oxide matrix. The results of this work are helpful for optimizing the performance of the optoelectronic devices based on the infrared emission of Ge nanocrystals.

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Enhanced red photoluminescence of quartz by silicon nanocrystals thin film deposition

Momeni

Pourgolestani

Taheri

et al. 2018

Applied Surface Science

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Red-luminescence band: A tool for the quality assessment of germanium and silicon nanocrystals

Cited by 5 publications

References 53 publications

Interplay of Quantum Confinement and Strain Effects in Type I to Type II Transition in GeSi Core–Shell Nanocrystals

Interplay of Quantum Confinement and Strain Effects in Type I to Type II Transition in GeSi Core–Shell Nanocrystals

Role of surface passivation on visible and infrared emission of Ge quantum dots formed by dewetting

Enhanced red photoluminescence of quartz by silicon nanocrystals thin film deposition

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