Journal ArticleDOI
Silicon quantum wire array fabrication by electrochemical and chemical dissolution of wafers
TLDR
In this paper, free standing Si quantum wires can be fabricated without the use of epitaxial deposition or lithography using electrochemical and chemical dissolution steps to define networks of isolated wires out of bulk wafers.Abstract:
Indirect evidence is presented that free‐standing Si quantum wires can be fabricated without the use of epitaxial deposition or lithography. The novel approach uses electrochemical and chemical dissolution steps to define networks of isolated wires out of bulk wafers. Mesoporous Si layers of high porosity exhibit visible (red) photoluminescence at room temperature, observable with the naked eye under <1 mW unfocused (<0.1 W cm−2) green or blue laser line excitation. This is attributed to dramatic two‐dimensional quantum size effects which can produce emission far above the band gap of bulk crystalline Si.read more
Citations
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Journal ArticleDOI
Surface stress effects on the resonant properties of silicon nanowires
TL;DR: In this paper, the surface Cauchy-Born model was used to quantify the coupled effects of surface stresses and boundary conditions on the resonant properties of silicon nanowires.
Journal ArticleDOI
Spatially resolved Raman measurements at electroluminescent porous n-silicon
Frank Kozlowski,Walter Lang +1 more
TL;DR: In this paper, the cross section of electroluminescent (EL) porous silicon layers (LEPOS) made from n and p-doped silicon has been investigated by means of micro Raman and photoluminescence (PL) spectroscopy to find the luminescence active zone in LEPOS.
Book ChapterDOI
Semiconductor device physics of conjugated polymers
Abstract: Conjugated polymers which can be processed to form thin, coherent films can be used as the active layers in semiconductor device structures. We have used the Durham precursor route to polyacetylene to fabricate a range of unipolar devices including Schottky barrier diodes, MIS diodes and MISFET’s. Although carrier mobilities are low, limited by thermally-activated transport between chains, these devices work well, and we find that these structures are remarkably free of surface states and bulk defect states with energy levels within the gap. The fundamental excitation of the trans-polyacetylene chain is the self-localised soliton-like kink defect in the bond alternation pattern along the chain; the soliton has associated with it an energy state at mid-gap of non-bonding pz character. We have been particularly concerned to demonstrate the formation of solitons from charges injected into the polyacetylene layer in these device structures, and have measured the changes in the optical properties that accompany soliton formation. For the MIS structures working in accumulation mode we find the ‘mid-gap’ transition from soliton level to the band edge at energies ranging between 0.55 eV (characteristic of the bulk) for polyacetylene on polymeric insulator layers to 0.8 eV when formed on silicon dioxide. We discuss this spread in energies in terms of the different surface structures at these different interfaces. We also show data for the characteristic vibrational excitations of the soliton, including both the IR-active translation modes and the Raman active amplitude modes.
Journal ArticleDOI
Electroluminescence from porous silicon with conducting polymer film contacts
TL;DR: In this article, visible electroluminescence with a peak wavelength of 6300 A was observed from forward-biased porous Si p-n diodes with conducting polymer contacts.
Journal ArticleDOI
Stress-induced band gap tuning in ⟨112⟩ silicon nanowires
TL;DR: In this article, the electronic band structures of hydrogenated silicon nanowires (SiNWs) could be significantly altered by axial stresses and axial compression could cause an indirect-to-direct band gap transition in SiNWs.
References
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Journal ArticleDOI
Electrolytic shaping of germanium and silicon
TL;DR: In this article, the properties of electrolyte-semiconductor barriers are described, with emphasis on germanium, and the use of these barriers in localizing electrolytic etching is discussed.
Journal ArticleDOI
Unusually low surface-recombination velocity on silicon and germanium surfaces.
TL;DR: It is found that a standard, widespread, chemical-preparation method for silicon, oxidation followed by an HF etch, results in a surface which from an electronic point of view is remarkably inactive, which has implications for the ultimate efficiency of silicon solar cells.
Journal ArticleDOI
Infrared spectroscopy of Si(111) and Si(100) surfaces after HF treatment: Hydrogen termination and surface morphology
TL;DR: In this paper, multiple internal infrared reflection spectroscopy has been used to identify the chemical nature of chemically oxidized and subsequently HF stripped silicon surfaces, and these very inert surfaces are found to be almost completely covered by atomic hydrogen.
Journal ArticleDOI
Hydrogen desorption kinetics from monohydride and dihydride species on silicon surfaces.
TL;DR: In this article, the authors measured hydrogen desorption from monohydride and dihydride species on crystalline-silicon surfaces using transmission Fourier-transform infrared (FTIR) spectroscopy.
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The structural and luminescence properties of porous silicon
Visible light emission due to quantum size effects in highly porous crystalline silicon
A. G. Cullis,Leigh T. Canham +1 more