Si nanocrystals in sic matrix and infrared spectroscopy of in a dielecric matrix

Download

index.pdf

Date

2010

Author

Gencer İmer, Arife

Metadata

Show full item record

Item Usage Stats

136
views

80
downloads

This study focuses on various aspects of nanocrystals embedded in a dielectric matrix. In the first part of this work, a new approach with the use of Fourier Transform Infrared spectroscopy (FTIR) in the nanocrystal analysis was developed and presented. Si and Ge nanocrystals embedded in SiO2 matrix were mainly studied. This new approach is based on the analysis of structural variations of SiO2 matrix during the formation of semiconductor nanocrystlas. It is shown that the chemical and structural variations of the host matrix are directly related to the precipitation of nanocrystals in it. This correlation provides valuable information about the presences of nanocrystals in the matrix. In the second part of this work, fabrication of SiC films with and without Si nanocrystals inclusions was studied. With this aim, stoichiometric SiC and Si rich SiC thin films were fabricated by using magnetron co-sputtering and Plasma Enhanced Chemical Vapor Deposition (PECVD) techniques. For SiC films, the structural and optical analyses were performed. For Si rich SiC films, the formation conditions of Si nanocrystals were investigated. Post annealing studies were carried out to track the evolution of the SiC matrix and formation of Si nanocrystals at different temperatures. Chemical and structural properties of the SiC host matrix were investigated with FTIR spectroscopy. Optimum conditions for the fabrication of stoichiometric SiC layers were determined. The crystallography of the nanocrystals was investigated by X-Ray Diffraction (XRD). The variation of the atomic concentrations and bond formations were investigated with X-Ray Photoelectron Spectroscopy (XPS). Raman spectroscopy and Transmission Electron Microscopy (TEM) were used to verify the formation of Si nanocrystals. We have shown that both single and multilayer Si nanocrystals can be fabricated in the amorphous SiC matrix for applications such as light emitting diodes and solar cells.

Subject Keywords

Physics., Spectroscopy.

URI

http://etd.lib.metu.edu.tr/upload/3/12611778/index.pdf
https://hdl.handle.net/11511/19495

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

The controlled drift detector as an x-ray imaging device for diffraction enhanced imaging Özkan, Çiğdem; Serin, Meltem; Department of Physics (2009) Diffraction Enhanced Imaging (DEI) is an X-ray imaging technique providing specific information about the molecular structure of a tissue by means of coherently scattered photons. A Controlled Drift Detector (CDD) is a novel 2D silicon imager developed to be used in X-ray imaging techniques. In this work a final (complete and detailed) analysis of DEI data taken with the CDD in the ELETTRA synchrotron light source facility in Trieste (Italy) in 2005, is presented and the applicability of both this new techn...
Gravitational waves and gravitational memory Korkmaz, Ali; Tekin, Bayram; Department of Physics (2018) We study the gravitational waves produced by compact binary systems in the linear regime of massless general relativity and calculate the gravitational memory produced by these waves on a detector.
Components of detector response function: Monte Carlo simulations and experiment Pekoz, Rengin; Can, Cüneyt (Wiley, 2006-11-01) Components of the response function of an HPGe detector for 32 keV incident photons (Ba K alpha x-rays) were studied using a Monte Carlo program. Physical mechanisms and the role of incident photons, detector x-rays, photoelectrons and Compton recoil and Auger electrons for each component were investigated. The position, intensity and shape of the components, particularly of the photoelectrons, were studied in detail. Two distinct components for photoelectron escape were identified by considering the fate o...
Escape of photoelectrons and Compton-scattered photons from an HPGe detector Can, Cüneyt (Wiley, 2003-07-01) The response function of a planar HPGe detector due to escape of photoelectrons and Compton-scattered photons was studied for a point source with 59.5 keV energy. It was shown that both mechanisms, in addition to Ge x-ray escape, leading to partial deposition of energy, could be observed in the same experiment. A Monte Carlo program was used to investigate these components of the response function. The results indicate that although the escape of scattered photons and Ge x-rays are of the same magnitude, th...
Nonlinear optical properties of semiconductor heterostructures Yıldırım, Hasan; Tomak, Mehmet; Department of Physics (2006) The nonlinear optical properties of semiconductor heterostructures, such as GaAsAl/GaAs alloys, are studied with analytic and numerical methods on the basis of quantum mechanics. Particularly, second and third-order nonlinear optical properties of quantum wells described by the various types of confining potentials are considered within the density matrix formalism. We consider a Pöschl-Teller type potential which has been rarely considered in this area. It has a tunable asymmetry parameter, making it a goo...

Citation Formats

A. Gencer İmer, “Si nanocrystals in sic matrix and infrared spectroscopy of in a dielecric matrix,” Ph.D. - Doctoral Program, Middle East Technical University, 2010.