Optical Characterization of Oxide Encapsulated Silicon Nanowires of Various Morphologies

2008 ◽  
Vol 8 (8) ◽  
pp. 4202-4206 ◽  
Author(s):  
Sharon M. King ◽  
Shweta Chaure ◽  
Satheesh Krishnamurthy ◽  
Werner J. Blau ◽  
Alan Colli ◽  
...  
Keyword(s):  
Silicon Nanowires ◽  
Silicon Oxide ◽  
Crystalline Silicon ◽  
Silicon Nanowire ◽  
Visible Spectrum ◽  
Optical Characterization ◽  
Nanocrystalline Silicon ◽  
Oxide Nanowires ◽  
Emitting Species

The optical properties of four different silicon nanowire structures were investigated. Two of the samples consisted of spheres of nanocrystalline silicon en-capsulated by silicon oxide nanowires, with other two consisting of crystalline silicon nanowires coated by silicon oxide shells. The nanostructures produced by oxide assisted growth consisted of spheres of crystalline silicon encapsulated by silicon oxide shells. The absorption and photoluminescence of the different structures of the sample are investigated. The emitting species responsible for photoluminescence across the visible spectrum are discussed.

scholarly journals Surface passivation and optical characterization of Al2O3/a-SiCx stacks on c-Si substrates

2013 ◽  
Vol 4 ◽  
pp. 726-731 ◽  
Author(s):  
Gema López ◽  
Pablo R Ortega ◽  
Cristóbal Voz ◽  
Isidro Martín ◽  
Mónica Colina ◽  
...  
Keyword(s):  
Wavelength Range ◽  
Surface Passivation ◽  
Crystalline Silicon ◽  
Surface Recombination ◽  
Chemical Vapor ◽  
Optical Characterization ◽  
Surface Recombination Velocity ◽  
Carrier Injection ◽  
Si Substrates

The aim of this work is to study the surface passivation of aluminum oxide/amorphous silicon carbide (Al2O3/a-SiCx) stacks on both p-type and n-type crystalline silicon (c-Si) substrates as well as the optical characterization of these stacks. Al2O3 films of different thicknesses were deposited by thermal atomic layer deposition (ALD) at 200 °C and were complemented with a layer of a-SiCx deposited by plasma-enhanced chemical vapor deposition (PECVD) to form anti-reflection coating (ARC) stacks with a total thickness of 75 nm. A comparative study has been carried out on polished and randomly textured wafers. We have experimentally determined the optimum thickness of the stack for photovoltaic applications by minimizing the reflection losses over a wide wavelength range (300–1200 nm) without compromising the outstanding passivation properties of the Al2O3 films. The upper limit of the surface recombination velocity (S eff,max) was evaluated at a carrier injection level corresponding to 1-sun illumination, which led to values below 10 cm/s. Reflectance values below 2% were measured on textured samples over the wavelength range of 450–1000 nm.

Structural and optical characterization of a dispersion of nanocavities in a crystalline silicon matrix

2004 ◽  
Vol 27 (1-3) ◽  
pp. 89-92 ◽  
Author(s):  
E. Leoni ◽  
R. El Bouyadi ◽  
L. Martinelli ◽  
G. Regula ◽  
E. Ntsoenzok ◽  
...  
Keyword(s):  
Crystalline Silicon ◽  
Optical Characterization ◽  
Silicon Matrix

Diffusion in Point Contact Reaction

2011 ◽  
Vol 309-310 ◽  
pp. 143-148
Author(s):  
Andriy Gusak ◽  
A.O. Kovalchuk ◽  
King Ning Tu
Keyword(s):  
Silicon Nanowires ◽  
Silicon Oxide ◽  
Silicon Nanowire ◽  
Point Contact ◽  
Atomic Layer ◽  
Point Contacts ◽  
Phase Growth ◽  
Stop And Go ◽  
Natural Oxide ◽  
Subsequent Phase

Recently) the point contact reactions between silicon nanowires (covered by natural oxide) and nanowires or nanodots of metals (nickel, cobalt, platinum) were discovered and studied. These reactions have at least three remarkable characteristics: (1) the reaction product phase is quite different from thin film or bulk reactions (for example, in Ni-Si reaction the appearing phase is Ni1Si1 or Ni1Si2, depending on the orientation of Si, instead of common Ni2Si phase); (2) Phase is formed not in the contact zone but, instead, near the wire tip or between two point contacts; (3) Subsequent phase growth of silicide inside silicon nanowire is a “stop-and-go” process consisting of waiting time before formation of critical island of each new atomic layer and then the fast filling of this new layer (mechanism suggested in 30-s for ideal crystals) Models of surface diffusion along and penetration through silicon oxide are presented. Nucleation models need more place and will be discussed in subsequent parts

Fabrication of silicon nanowire network in aluminum thin films

2005 ◽  
Vol 862 ◽  
Author(s):  
Vincent H. Liu ◽  
Husam H. Abu-Safe ◽  
Hameed A. Naseem ◽  
William D. Brown
Keyword(s):  
Thin Film ◽  
Silicon Nanowires ◽  
Silicon Nanowire ◽  
Vertical Direction ◽  
X Ray ◽  
Nanowire Network ◽  
Aluminum Thin Film ◽  
Nanowire Networks ◽  
Scanning Electron

AbstractThe formation of isolated silicon nanowires and silicon nanowire networks using aluminum thin film is investigated. The formation mechanism of the network mainly depends on the diffusion of silicon in the aluminum thin film. The silicon stops at the film grain boundaries. The continuous accumulations of silicon at these boundaries give raise to a continuous network of silicon nanowires. Characterization of the nanowires has been done using scanning electron microscopy and energy dispersive x-ray spectroscopy. These results are unique in the fact that the nanowires found are grown in a horizontal fashion instead of the more common vertical direction. Most of the nanowires have a diameter of about 60 nm and a length of over 10 μm.

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