Spectrla analysis technique for periodically time-varying linear systems.

Tohumoğlu, Gülay


Spectrophotometric and amperometric biosensors based on conducting polymers of 1-Benzyl-2,5-DI(Thiophen-2-YL)-1H-Pyrrole and (4,7-Dithien-2-YL-2,1,3-Benzothiadiazole)
Tanrıverdi, Simla; Toppare, Levent Kamil; Timur, Suna; Department of Polymer Science and Technology (2012)
In this thesis, two different biosensors based on conducting polymers of (4,7-dithien-2-yl-2,1,3-benzothiadiazole) (TBTD) and 1-benzyl-2,5 di(thiophene-2-yl)-1H-Pyrrole (SNBS) were prepared. Electrochemical technique was used for polymerization of conducting polymers and two different immobilization techniques were used for immobilizing enzyme into the conducting polymer matrices. The proposed biosensors were characterized and optimized. Optimum pH, thickness, enzyme amount were determined and linearity, re...
Spectroscopic ellipsometry study of Si nanocrystals embedded in a SiOx matrix: Modeling and optical characterization
Ilday, Serim; Nogay, Gizem; Turan, Raşit (2014-11-01)
In this work, we report on a spectroscopic ellipsometry study of thin films of silicon nanocrystals embedded in a SiOx matrix that is performed to better understand how substoichiometric SiOx species affect the optical properties of these systems. The silicon nanocrystals are fabricated in a SiOx matrix by thermal annealing of magnetron-sputtered thin films in a wide range of x values (0< x< 2) in order to produce every possible substoichiometric SiOx species in various fractions. A generic optical model to...
Spectroscopic intensities as measures of order parameter close to order-disorder transitions
Yurtseven, Hasan Hamit (Springer Science and Business Media LLC, 1988-01-01)
The infrared and Raman intensities can be related to the order parameter close to order-disorder phase transitions in crystal systems. In the present study this relationship has been obtained and compared with our experimental results for ammonium halides. Our predictions give satisfactory agreement with the observations in these crystals. It is proposed that the FTIR techniques can be appropriately used to evaluating the order parameter in various crystal systems.
Spectroscopic ellipsometry investigation of optical properties of beta-Ga2S3 single crystals
Işık, Mehmet; Hasanlı, Nızamı; Gasanova, L. (Elsevier BV, 2018-12-01)
Ga2S3 single crystals were studied by x-ray diffraction (XRD), energy dispersive spectroscopy and spectroscopic ellipsometry measurements. XRD pattern of the sample is well-matched with reported hexagonal structure of beta-Ga2S3 . The spectra of real and imaginary parts of complex dielectric function (epsilon = epsilon(1) + epsilon(2)) and refractive index (N = n + ik) were plotted in the 1.2-6.2 eV range according to results of ellipsometric data. The e 2 -spectrum and analyses of absorption coefficient po...
Spectroelectrochemical and Photovoltaic Characterization of a Solution-Processable n-and-p Type Dopable Pyrrole-Bearing Conjugated Polymer
Baran, Derya; Balan, Abidin; Esteban, Beatriz-Meana; Neugebauer, Helmut; Sariciftci, Niyazi Serdar; Toppare, Levent Kamil (Wiley, 2010-12-15)
D-A-D-type polymers are of high interest in the field of photovoltaics and electrochromism. In this study we report the synthesis and electrochemical properties of PPyBT along with its photophysical properties and photovoltaic performance. PPyBT is soluble in common organic solvents and both n- and p-type dopable, which is a desired property for conjugated polymers. During electrochemistry studies, the onset potentials of the polymer were determined as +0.2V for oxidation and -1.4V for reduction. Using thes...
Citation Formats
G. Tohumoğlu, “Spectrla analysis technique for periodically time-varying linear systems.,” Middle East Technical University, 1986.