الفهرس 
Luminescence
ExperimentalOnly 14 pages are availabe for public view
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Abstract
The thesis comprises four main chapters; introduction, experimental and results and discussion, these chapters can be summarized as: Chapter1: Introduction This chapter provides a short note about photoluminescence. In addition, the theory of luminescence and the types of transition, kinetics of luminescence and decay mechanisms was also discussed in the chapter. This part also discussed the techniques to study the optical properties of condensed matter based on the photoluminescence of the matter. Also, it focused on the treatment and how to determine the optical parameters of the materials. Chapter 2: Experimental This chapter contains a description of the chemicals and materials, synthesis process of the PMMA and RhB doped PMMA, FT-IR and XRD of the synthesized composite, study techniques and the constructions of these techniques. Chapter 3: Results & Discussion This chapter includes the results and discussion of two subparts. Part 1: Measurements of photoluminescence characteristics This part aims to determine the photoluminescence characteristics for the materials under study. Absorption spectra, transmittance spectra, emission spectra, laser photoluminescence, temperature dependent photoluminescence and florescence lifetime were measured using UV-Vis spectrophotometer, fluorometer, laser photoluminescence experiment with a cryostat and time resolved photoluminescence spectroscopy. Reflectance spectra was calculated from absorbance and transmittance spectra using the relation 𝑅 = 1 − √𝑇. 𝑒𝐴 Part 2: Determination of optical parameters In this part direct optical energy gap was measured by using the relation (𝛼ℎ𝜐)2 = 𝐵(ℎ𝜐 − 𝐸𝑔) By plotting (𝛼ℎ𝜐)2 versus ℎ𝜐, the intersection points between the extrapolated part of the curves and the photon energy axis are the values of the energy gap. Then the extinction parameter and refractive index was measured using the relations 𝑘 = 𝛼𝜆 4𝜋 , And 𝑛 = ( 1 + 𝑅 1 − 𝑅 ) + √ 4𝑅 (1 − 𝑅)2 − 𝑘2 By using the single oscillator model of Wemple and Di- Domenico (𝑛2 − 1)−1 = 𝐸𝑜 𝐸𝑑 − 1 𝐸𝑜𝐸𝑑 (ℎ𝜐)2 The dispersion energy and single oscillator energy was measured. Using the single term Sellmeier oscillator model, long distance refractive index (𝑛∞), average inter-band oscillator wavelength (𝜆𝑜), average oscillator strength (𝑆𝑜) and the lattice dielectric constant (𝜀𝑙) and the ratio of carrier amount to the electron effective mass (𝑒2⁄𝜋𝑐2)(𝑁⁄𝑚∗) were calculated using the following equations 𝑛∞ 2 − 1 𝑛2 − 1 = 1 − ( 𝜆𝑜 𝜆 ) 2 𝑆𝑜 = 𝑛∞ 2 − 1 𝜆𝑜 from the linear fitted lines of (𝑛2 − 1)−1 against 𝜆−2 and 𝑛2 against 𝜆2one may calculate 𝑛∞, 𝜆𝑜, 𝑆𝑜, 𝜀𝑙 and (𝑒2⁄𝜋𝑐2)(𝑁⁄𝑚∗). Finally, the optical conductivity was measured by using the relation 𝜎 = 𝛼𝑛𝑐