Thickness-dependent optimization of Er3+ light emission from silicon-rich silicon oxide thin films

Cueff, Sébastien; Labbé, Christophe; Jambois, O.; Garrido, B.; Portier, X.; Rizk, R.

doi:10.1186/1556-276x-6-395

Cited by 15 publications

(27 citation statements)

References 23 publications

(36 reference statements)

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“…The dynamic permittivity ε r , used here as a free fit parameter, is shown to be ε r = 3.0 ± 0.2 for all layers, indicating that there is no significant change in the composition when the thickness is increased. Such a result is consistent with our previous analysis of the composition profiles as a function of thickness [28]. We also report in Fig.…”

Section: Device Processing and Electrical Characteristicssupporting

confidence: 82%

“…According to this calculation the thickness decrease cannot explain itself the 4-order increase of current density. Consequently, this thickness dependence of J max exp is more likely to be the result of a change in the atomic arrangement within the active layers [28].…”

Section: Device Processing and Electrical Characteristicsmentioning

confidence: 99%

“…The composition of the active layer was found to be unchanged when the film thickness was varied; further details of the deposition, as well as structural and compositional investigations, can be found elsewhere [28]. The deposition temperature was maintained at 500°C, corresponding to the optimum luminescent properties determined in a previous study [29].…”

Section: Device Processing and Electrical Characteristicsmentioning

confidence: 99%

“…Interestingly, the thinnest samples present the double advantage of showing both high J and low V th and appear, at this stage, as the most suitable for highly efficient LEDs. As the same composition and the same transport mechanism prevail in all samples, the observed thickness-dependence of J and V th somehow result either from the thickness itself or from a thickness-dependent arrangement of atoms inside the layer [28]. To investigate the likelihood of one or the other phenomenon, we use the relation describing the variation of J vs. d al in PF mechanism (Eq.…”

Section: Device Processing and Electrical Characteristicsmentioning

confidence: 99%

“…Hence, for a given Si excess and thermal treatment, a 'thin' film (<100-150 nm) contains a high number of dispersed Si atoms that are preferentially arranged as defects (Silicon Oxygen-Deficient Centers -SiODC or Non-Bridging Oxygen Hole Centers -NBOHC) or very small agglomerates [28,31,32]. On the other hand, the same amount of Si excess in a 'thick' film (>100-150 nm) subject to the same heat treatment would preferentially agglomerate in well-defined Si-ncs [28,31,32]. In thin films, this leads to a high number of structural defects and isolated atoms scattered throughout the layer, creating a high density of energy states close to the band edges.…”

Section: Device Processing and Electrical Characteristicsmentioning

confidence: 99%

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Structural factors impacting carrier transport and electroluminescence from Si nanocluster-sensitized Er ions

Cueff¹,

Labbé²,

Jambois³

et al. 2012

Opt. Express

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Abstract:We present an analysis of factors influencing carrier transport and electroluminescence (EL) at 1.5 µm from erbium-doped silicon-rich silica (SiO x ) layers. The effects of both the active layer thickness and the Siexcess content on the electrical excitation of erbium are studied. We demonstrate that when the thickness is decreased from a few hundred to tens of nanometers the conductivity is greatly enhanced. Carrier transport is well described in all cases by a Poole-Frenkel mechanism, while the thickness-dependent current density suggests an evolution of both density and distribution of trapping states induced by Si nanoinclusions. We ascribe this observation to stress-induced effects prevailing in thin films, which inhibit the agglomeration of Si atoms, resulting in a high density of sub-nm Si inclusions that induce traps much shallower than those generated by Si nanoclusters (Si-ncs) formed in thicker films. There is no direct correlation between high conductivity and optimized EL intensity at 1.5 µm. Our results suggest that the main excitation mechanism governing the EL signal is impact excitation, which gradually becomes more efficient as film thickness increases, thanks to the increased segregation of Si-ncs, which in turn allows more efficient injection of hot electrons into the oxide matrix. Optimization of the EL signal is thus found to be a compromise between conductivity and both number and degree of segregation of Si-ncs, all of which are governed by a combination of excess Si content and sample thickness. This material study has strong implications for many electricallydriven devices using Si-ncs or Si-excess mediated EL. USSR 5, 685-687 (1938). ©2012 Optical Society of America

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Section: Device Processing and Electrical Characteristicssupporting

confidence: 82%

Section: Device Processing and Electrical Characteristicsmentioning

confidence: 99%

Section: Device Processing and Electrical Characteristicsmentioning

confidence: 99%

Section: Device Processing and Electrical Characteristicsmentioning

confidence: 99%

Section: Device Processing and Electrical Characteristicsmentioning

confidence: 99%

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Structural factors impacting carrier transport and electroluminescence from Si nanocluster-sensitized Er ions

Cueff¹,

Labbé²,

Jambois³

et al. 2012

Opt. Express

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Highly Efficient Infrared Quantum Cutting in Tb³⁺−Yb³⁺ Codoped Silicon Oxynitride for Solar Cell Applications

Labbé

Cardin

et al. 2013

Advanced Optical Materials

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A high effi ciency infrared quantum cutting effect in a Tb 3+ -Yb 3+ codoped silicon oxynitride system is demonstrated. The thin fi lms are deposited on Si substrates by reactive magnetron co-sputtering of a Si target topped with Tb 4 O 7 and Yb 2 O 3 chips under pure nitrogen plasma. The photoluminescence dynamics are investigated, revealing a quantum effi ciency of this system at 980 nm up to 197% for the higher Yb 3+ concentration. Thus, via a cooperative transfer mechanism between Tb 3+ and Yb 3+ , an absorbed UV-visible photon gives rise to almost two emitted IR photons. Such a down-conversion effect is demonstrated upon indirect excitation of energy donors, via defect states in the host matrix. These down-converter fi lms could be directly and easily integrated on top of the Si-based solar cell to improve the photoelectric conversion effi ciency at a lower cost. An evaluation of the additional external quantum effi ciency is deduced from this optical system and found to be almost 2%.Adv. Optical Mater. 2013, 1, 855-862 856 wileyonlinelibrary.com

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Undoped and Nd³⁺ doped Si-based single layers and superlattices for photonic applications

Khomenkova

Labbé

Portier

et al. 2013

Phys. Status Solidi A

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This work presents the benefits of the superlattice approach to control light emission properties of materials with Si nanoclusters and rare‐earth ions. The undoped and Nd3+‐doped both Si‐rich‐SiO2 single layers and Si‐rich‐SiO2/SiO2 superlattices were grown by radio frequency magnetron sputtering. Their properties were investigated by means of spectroscopic ellipsometry, Fourier infrared transmission spectroscopy, transmission electron microscopy, and photoluminescence (PL) methods versus deposition conditions, annealing treatment, and superlattice design (doping and thickness of alternated sublayers). An intense Nd3+ emission from as‐deposited single layers and superlattices was observed. The lower annealing temperature (below 900 °C) of the single layers and superlattices favors the formation of amorphous Si clusters that act as effective sensitizers of rare‐earth ions. The highest Nd3+ PL intensity was achieved after a conventional annealing at about 600–800 °C in nitrogen flow for all samples. Crystallized Si‐nanoclusters were formed in Si‐rich‐SiO2 single layers upon annealing at 1000–1100 °C, whereas their formation in the superlattices occurred at higher temperatures (1100–1150 °C). The mechanism of Nd ions' excitation via energy transfer from Si‐nanoclusters and/or matrix defects, if any, is discussed.

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Thickness-dependent optimization of Er3+ light emission from silicon-rich silicon oxide thin films

Cited by 15 publications

References 23 publications

Structural factors impacting carrier transport and electroluminescence from Si nanocluster-sensitized Er ions

Structural factors impacting carrier transport and electroluminescence from Si nanocluster-sensitized Er ions

Highly Efficient Infrared Quantum Cutting in Tb³⁺−Yb³⁺ Codoped Silicon Oxynitride for Solar Cell Applications

Undoped and Nd³⁺ doped Si-based single layers and superlattices for photonic applications

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Thickness-dependent optimization of Er3+ light emission from silicon-rich silicon oxide thin films

Cited by 15 publications

References 23 publications

Structural factors impacting carrier transport and electroluminescence from Si nanocluster-sensitized Er ions

Structural factors impacting carrier transport and electroluminescence from Si nanocluster-sensitized Er ions

Highly Efficient Infrared Quantum Cutting in Tb3+−Yb3+ Codoped Silicon Oxynitride for Solar Cell Applications

Undoped and Nd3+ doped Si-based single layers and superlattices for photonic applications

Contact Info

Product

Resources

About

Highly Efficient Infrared Quantum Cutting in Tb³⁺−Yb³⁺ Codoped Silicon Oxynitride for Solar Cell Applications

Undoped and Nd³⁺ doped Si-based single layers and superlattices for photonic applications