Broadband infrared photoluminescence in silicon nanowires with high density stacking faults

Li, Yang; Liu, Zhihong; Lu, Xiaoxiang; Su, Zhihua; Wang, Yanan; Li, Rui; Wang, Dunwei; Jian, Jie; Lee, Joon Hwan; Wang, Haiyan; Yu, Qingkai; Bao, Jiming

doi:10.1039/c4nr05410e

Cited by 15 publications

(13 citation statements)

References 38 publications

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“…The emission peak is centered around 750 nm, that is, 1.65 eV and exhibits a large superposition with the solar spectrum in the visible region. The origin of the emission still has to be verified, as similar results have already been reported in cubic Si nanostructures (NWs, porous Si, , and nanoparticles) and thus cannot be directly ascribed to hexagonal Si. Generally, visible emission in Si nanostructures has been explained as a consequence of confinement. ,,, Confinement is expected to cause a blueshift of the electronic states, raising the value of the band gap while increasing the efficiency of radiative recombination thanks to carrier concentration and indirect space delocalization .…”

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confidence: 72%

Nature of Hexagonal Silicon Forming via High-Pressure Synthesis: Nanostructured Hexagonal 4H Polytype

et al. 2018

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Hexagonal Si allotropes are expected to enhance light absorption in the visible range as compared to common cubic Si with diamond structure. Therefore, synthesis of these materials is crucial for the development of Si-based optoelectronics. In this work, we combine in situ high-pressure high-temperature synthesis and vacuum heating to obtain hexagonal Si. High pressure is one of the most promising routes to stabilize these allotropes. It allows one to obtain large-volume nanostructured ingots by a sequence of direct solid-solid transformations, ensuring high-purity samples for detailed characterization. Thanks to our synthesis approach, we provide the first evidence of a polycrystalline bulk sample of hexagonal Si. Exhaustive structural analysis, combining fine-powder X-ray and electron diffraction, afforded resolution of the crystal structure. We demonstrate that hexagonal Si obtained by high-pressure synthesis correspond to Si-4H polytype (ABCB stacking) in contrast with Si-2H (AB stacking) proposed previously. This result agrees with prior calculations that predicted a higher stability of the 4H form over 2H form. Further physical characterization, combining experimental data and ab initio calculations, have shown a good agreement with the established structure. Strong photoluminescence emission was observed in the visible region for which we foresee optimistic perspectives for the use of this material in Si-based photovoltaics.

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confidence: 72%

Nature of Hexagonal Silicon Forming via High-Pressure Synthesis: Nanostructured Hexagonal 4H Polytype

et al. 2018

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“…Given the large emission spectra of silicon 37 , silicon nitride 16 , and the metallic coating on the cantilever backside, in our case gold 35 , the choice of the emission filter is not crucial if compared to fluorescence imaging of conventional organic fluorophores characterized by narrow emission spectra. In Fig.…”

Section: Resultsmentioning

confidence: 99%

Synchronous, Crosstalk-free Correlative AFM and Confocal Microscopies/Spectroscopies

Fernandes

Saavedra-Villanueva

Margeat

et al. 2020

Sci Rep

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Microscopies have become pillars of our characterization tools to observe biological systems and assemblies. Correlative and synchronous use of different microscopies relies on the fundamental assumption of non-interference during images acquisitions. In this work, by exploring the correlative use of Atomic Force Microscopy and confocal-Fluorescence-Lifetime Imaging Microscopy (AFM-FLIM), we quantify cross-talk effects occurring during synchronous acquisition. We characterize and minimize optomechanical forces on different AFM cantilevers interfering with normal AFM operation as well as spurious luminescence from the tip and cantilever affecting time-resolved fluorescence detection. By defining non-interfering experimental imaging parameters, we show accurate real-time acquisition and two-dimensional mapping of interaction force, fluorescence lifetime and intensity characterizing morphology (AFM) and local viscosity (FLIM) of gel and fluid phases separation of supported lipid model membranes. Finally, as proof of principle by means of synchronous force and fluorescence spectroscopies, we precisely tune the lifetime of a fluorescent nanodiamond positioned on the AFM tip by controlling its distance from a metallic surface. This opens up a novel pathway of quench sensing to image soft biological samples such as membranes since it does not require tip-sample mechanical contact in contrast with conventional AFM in liquid.We characterized and quantified these effects by operating the AFM in the reverse-tip imaging configuration 36 . The 3/14

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“…But also the contribution from the defect states at the surface or dislocations or stacking faults near surface or at Si nanowires can be effective in NIR light emission at around 1350 nm. An infrared photoluminescence was observed in Si nanowires with high density of stacking faults [44]. But emission is rather very broad and ranges from 900 nm up to 1650 nm.…”

Section: Nm Light Sourcementioning

confidence: 99%

1320 nm Light Source From Deuterium Treated Silicon

Kalem

2020

IEEE Open J. Nanotechnol.

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We report an efficient room temperature photon source at 1320 nm telecommunication wavelength from nanostructured silicon surface. The activation of this light source was realized by treating the surface of Si wafer by vapor of heavy water (D2O) containing a mixture of hydrofluoric and nitric acids. Treatment without deuterium generates an intense light emission band at the band-edge of Si, while the deuterium treatment alone creates a strong emission band at 1320 nm in the near infrared. It was found that the deuterium is actively involved in the formation of a nanostructured Si surface as evidenced from relative strength of the Si-O vibrational modes and presence of N-D bondings. The origin of this photon source was discussed in terms of oxygen related defect states and dislocations. The Si surface treated by Deuterium containing mixture exhibits a strong rectifying electrical activity as it is demonstrated by Schottky diodes fabricated on these wafers. Being compatible with mature silicon circuitry, the source may find applications in photonics and optoelectronics.

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Broadband infrared photoluminescence in silicon nanowires with high density stacking faults

Cited by 15 publications

References 38 publications

Nature of Hexagonal Silicon Forming via High-Pressure Synthesis: Nanostructured Hexagonal 4H Polytype

Nature of Hexagonal Silicon Forming via High-Pressure Synthesis: Nanostructured Hexagonal 4H Polytype

Synchronous, Crosstalk-free Correlative AFM and Confocal Microscopies/Spectroscopies

1320 nm Light Source From Deuterium Treated Silicon

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