Optical property investigation of SiGe nanocrystals formed by electrochemical anodization

Pan, S.W.; Bi, Zhen; Chen, S.Y.; Cheng, Li; Huang, Wei; Lai, Hongkai

doi:10.1016/j.apsusc.2011.07.141

Cited by 9 publications

(3 citation statements)

References 28 publications

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“…The properties of such structures can be tuned by altering the stoichiometric parameter x in Si 1−x Ge x (i.e. the Ge fraction) and by controlling the size of NCs [3,4,6,7]. In addition, strain engineering can be utilized to determine the bandgap of the SiGe nanocrystals (NCs) for the purpose of enhancing energy conversion efficiency and optical properties [1,2,8].…”

Section: Introductionmentioning

confidence: 99%

Efficacy of annealing and fabrication parameters on photo-response of SiGe in TiO₂ matrix

Sultan¹,

Guðmundsson²,

Manolescu³

et al. 2019

Nanotechnology

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SiGe nanoparticles dispersed in a dielectric matrix exhibit properties different from those of bulk and have shown great potential in devices for application in advanced optoelectronics. Annealing is a common fabrication step used to increase crystallinity and to form nanoparticles in such a system. A frequent downside of such annealing treatment is the formation of insulating SiO 2 layer at the matrix/SiGe interface, degrading the optical properties of the structure. An annealing process that could bypass this downside would therefore be of great interest. In this work, a short-time furnace annealing of a SiGe/TiO 2 system is applied to obtain SiGe nanoparticles without formation of the undesired SiO 2 layer between the dielectric matrix (TiO 2 ) and SiGe. The structures were prepared by depositing alternate layers of TiO 2 and SiGe films, using directcurrent magnetron sputtering technique. A wide range spectral response with a responsethreshold up to ∼1300 nm was obtained, accompanied with an increase in photo-response of more than two-orders of magnitude. Scanning electron microscopy, transmission electron microscopy, energy-dispersive x-ray spectroscopy and grazing incidence x-ray diffraction were used to analyze the morphological changes in respective structures. Photoconductive properties were studied by measuring photocurrent spectra using applied dc-voltages at various temperatures.

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Section: Introductionmentioning

confidence: 99%

Efficacy of annealing and fabrication parameters on photo-response of SiGe in TiO₂ matrix

Sultan¹,

Guðmundsson²,

Manolescu³

et al. 2019

Nanotechnology

View full text Add to dashboard Cite

show abstract

“…[1][2][3] It is expected that the bandgap energy of SiGe NPs with the same size depends on the ratio of Si=Ge. [4][5][6][7] Commonly, the PL emission mechanism on this system is ascribed to quantum confinement effect or defect states electron transition. There exist a large number of nonirradiative defects in and=or around NPs, which is the main reason for quenching of the exciton recombination in NPs.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Photoluminescence Intensity of Silicon–Germanium Nanoparticles: Silica Thin Films by Annealing in Forming Gas

Zhong

2014

Spectroscopy Letters

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Silicon-germanium nanoparticles are prepared by ion implantation and annealing method. Further annealing treatment is carried out in forming gas to passivate nonradiative defects around nanoparticles. Time-resolved photoluminescence measurements were examined to reveal the local environment surrounding the nanoparticles. With the increase in oxygen gas content, photoluminescence intensity from specimen is enhanced by $5 times and its decay time s decreases from 23.2 to 1.6 ms. Oxygen gas is considered to be an effective passivating gas for this kind of specimen.

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“…These NCs present unique and interesting size-dependent physical properties for a wide range of application including lighting, non-volatile memories, and electronic and photovoltaic applications [1–3]. SiGe nanostructures exhibit a stronger quantum confinement effect than Si NCs [4] and have the advantage of a bandgap fine-tuning by varying the Ge atomic fraction [5–6]. These properties are useful for optoelectronic devices working in the visible to far-infrared region [4,7].…”

Section: Introductionmentioning

confidence: 99%

Fabrication and characterization of Si₁₋_xGe_x nanocrystals in as-grown and annealed structures: a comparative study

Sultan

Maraloiu

Stavarache

et al. 2019

Beilstein J. Nanotechnol.

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Multilayer structures comprising of SiO2/SiGe/SiO2 and containing SiGe nanoparticles were obtained by depositing SiO2 layers using reactive direct current magnetron sputtering (dcMS), whereas, Si and Ge were co-sputtered using dcMS and high-power impulse magnetron sputtering (HiPIMS). The as-grown structures subsequently underwent rapid thermal annealing (550–900 °C for 1 min) in N2 ambient atmosphere. The structures were investigated using X-ray diffraction, high-resolution transmission electron microscopy together with spectral photocurrent measurements, to explore structural changes and corresponding properties. It is observed that the employment of HiPIMS facilitates the formation of SiGe nanoparticles (2.1 ± 0.8 nm) in the as-grown structure, and that presence of such nanoparticles acts as a seed for heterogeneous nucleation, which upon annealing results in the periodically arranged columnar self-assembly of SiGe core–shell nanocrystals. An increase in photocurrent intensity by more than an order of magnitude was achieved by annealing. Furthermore, a detailed discussion is provided on strain development within the structures, the consequential interface characteristics and its effect on the photocurrent spectra.

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Optical property investigation of SiGe nanocrystals formed by electrochemical anodization

Cited by 9 publications

References 28 publications

Efficacy of annealing and fabrication parameters on photo-response of SiGe in TiO₂ matrix

Efficacy of annealing and fabrication parameters on photo-response of SiGe in TiO₂ matrix

Enhanced Photoluminescence Intensity of Silicon–Germanium Nanoparticles: Silica Thin Films by Annealing in Forming Gas

Fabrication and characterization of Si₁₋_xGe_x nanocrystals in as-grown and annealed structures: a comparative study

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Optical property investigation of SiGe nanocrystals formed by electrochemical anodization

Cited by 9 publications

References 28 publications

Efficacy of annealing and fabrication parameters on photo-response of SiGe in TiO2 matrix

Efficacy of annealing and fabrication parameters on photo-response of SiGe in TiO2 matrix

Enhanced Photoluminescence Intensity of Silicon–Germanium Nanoparticles: Silica Thin Films by Annealing in Forming Gas

Fabrication and characterization of Si1−xGex nanocrystals in as-grown and annealed structures: a comparative study

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Efficacy of annealing and fabrication parameters on photo-response of SiGe in TiO₂ matrix

Efficacy of annealing and fabrication parameters on photo-response of SiGe in TiO₂ matrix

Fabrication and characterization of Si₁₋_xGe_x nanocrystals in as-grown and annealed structures: a comparative study