Enhanced first-order Raman scattering from arrays of vertical silicon nanowires

Khorasaninejad, Mohammadreza; Walia, Jaspreet; Saini, Simarjeet S.

doi:10.1088/0957-4484/23/27/275706

Cited by 70 publications

(54 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A correlation between conjugation length and the relative intensity of the peaks at 1440 cm ¹1 was found. Improvement of Raman scattering with diameter decrease and morphology dependence have been also evidenced when studying Si nanowires (SiNW), 42 which agrees with the results obtained in the current study.…”

Section: ¹1supporting

confidence: 91%

Electro-synthesis and Characterization of Polymer Nanostructures from Terthiophene Using Silica Mesoporous Films as Template

et al. 2014

View full text Add to dashboard Cite

Nanostructures of poly(2,2′:5′,2′′-terthiophene) have been synthesized using only electrochemical techniques. To this end, a porous silica film modified platinum disc was used as working electrode (Pt|(SiO 2 ) n ). The silica coating acts as a template so that the subsequent electro-polymerization occurs in their confined space pores, perpendicular to the electrodic surface. The current response of the obtained polymeric deposit is much greater than that exhibited by the solid massive polymer (generated under identical conditions but without template), accounting for the significant increase of the p-doping/undoping charge. Template removal was accomplished by treating the deposits with HF solutions. It was demonstrated that as the template is removed, the charge of the nanostructured electrodes increases even more. Electro-deposit characterization was supplemented using transmission electron microscopy, TEM, and FT-Raman spectroscopy, which revealed the obtaining of electrodes modified with polymeric nanostructures vertically aligned upon the electrode surface. Thus, a methodology employing solely electrochemical techniques that enables the obtainment of polymeric nanodeposits directly on the electrode surface was proposed. This approach allows foreseeing a significant progress in applications wherein these materials are useful, since this methodology, first tested for polythiophene, is applicable to various starting units capable of being electro-synthesized.

show abstract

Section: ¹1supporting

confidence: 91%

Electro-synthesis and Characterization of Polymer Nanostructures from Terthiophene Using Silica Mesoporous Films as Template

et al. 2014

View full text Add to dashboard Cite

show abstract

“…The resonance diameter was observed in this study because of the small increments in diameter used, as opposed to the larger increments studied in previous works. Previous Raman scattering studies on vertically oriented crystalline silicon nanowires arranged in square lattices [19,20] have not shown any local heating, even at laser input intensities an order of magnitude higher than the one used in this study. This result confirms that lower thermal conductivities are seen in GaAs nanowires as compared to Si nanowires.…”

Section: Resultscontrasting

confidence: 60%

“…As a comparison, a temperature increase of 50 K was observed in single wall carbon nanotubes embedded in polydimethylsilicate substrate for an incident intensity of 318 mW/mm 2 [4]. The large Raman scattering enhancement is an indication of strong electric field confinement within the nanowires [19,20], leading to higher temperatures. The resonance diameter was observed in this study because of the small increments in diameter used, as opposed to the larger increments studied in previous works.…”

Section: Resultsmentioning

confidence: 94%

Diameter dependent heating in GaAs nanowires

Walia

Dhindsa

Flannery

et al. 2014

14th IEEE International Conference on Nanotechnology

View full text Add to dashboard Cite

The photo-thermal properties of vertically etched gallium arsenide nanowire arrays are examined using Raman spectroscopy. The nanowires are arranged in square lattices with a constant pitch of 400 nm, and diameters ranging from 50 to 155 nm. The arrays were illuminated using a 532 nm laser with an incident energy density of 10 W/mm 2 . Nanowire temperatures were highly dependent on the nanowire diameter, and were determined by measuring the spectral redshift for both TO and LO phonons. The highest temperatures were observed for the 95 nm diameter nanowires, whose top facets and sidewalls heated up to 600 K and 440 K, respectively, and decreased significantly for the smaller or larger diameters studied. The findings also demonstrate that a photonic lattice consisting of vertically oriented GaAs nanowires allows for optimization of the photo-thermal effect.978-1-4799-5622-7/$31.00 ©2014 IEEE

show abstract

“…Lift-off is carried out by soaking the sample in a solvent stripper (remover PG from Microchem). Inductively coupled plasma-reactive ion etching (ICP-RIE) is performed to etch the nanoridges [32]. The passivation layer generated during the etching process is removed by placing the device in an oxygen plasma (power: 150 W) for 5 min.…”

Section: A Experimental Demonstration Of Polarization-dependent Scatmentioning

confidence: 99%

Efficient polarization beam splitter pixels based on a dielectric metasurface

Khorasaninejad¹,

Zhu²,

Crozier³

2015

Optica

141

View full text Add to dashboard Cite

The polarization dependence of the reflection, refraction, and diffraction of electromagnetic waves from materials is measured in applications that extend from small (e.g., ellipsometry of semiconductor chips) to large scales (e.g., remote sensing for planetary science and weather radar). Such applications employ polarimeters that are in turn based on devices with polarization-selective absorption or reflection/refraction properties (e.g., prisms). The latter devices are generally bulky, thereby limiting their integration into compact systems. The former devices are inherently lossy, as they function by absorbing the unwanted polarization. Here, we experimentally demonstrate a conceptually novel method for pixellevel polarimetry. Each pixel contains amorphous-silicon nanoridges and deflects incident light in a polarizationdependent manner. As photons are sorted by polarization rather than filtered, the approach permits high efficiency. A high transmission efficiency of 90% and a high extinction ratio of 15 times are demonstrated.

show abstract

Enhanced first-order Raman scattering from arrays of vertical silicon nanowires

Cited by 70 publications

References 28 publications

Electro-synthesis and Characterization of Polymer Nanostructures from Terthiophene Using Silica Mesoporous Films as Template

Electro-synthesis and Characterization of Polymer Nanostructures from Terthiophene Using Silica Mesoporous Films as Template

Diameter dependent heating in GaAs nanowires

Efficient polarization beam splitter pixels based on a dielectric metasurface

Contact Info

Product

Resources

About