Effect of UV irradiation time on the structure and optical properties of Rose Bengal thin films | ||||
| Scientific Journal for Damietta Faculty of Science | ||||
| Article 3, Volume 4, Issue 1, 2015, Page 23-34 PDF (1.2 MB) | ||||
| Document Type: Original articles | ||||
| DOI: 10.21608/sjdfs.2015.194325 | ||||
 View on SCiNiTO | ||||
| Authors | ||||
H. M. Zeyada  1; M I Youssif1; N A El-Ghamaz1; M EO Aboderbala2
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| 1Department of physics, Faculty of science,34517, University of Damietta. Egypt | ||||
| 2Department of physics, Faculty of science, AlJabl Al Gharbi University, Libya | ||||
| Abstract | ||||
| Optical properties of pristine and UV irradiated Rose Bengal (RB) films have been investigated using transmittance and reflectance methods. The refractive index (n) and extinction coefficient (k) of RB films were directly calculated from absolute values of transmission and reflection spectra. Single oscillator parameters and the Drude model of free carrier absorption have been used for the analysis of refractive index dispersion. The fundamental absorption edge data were analyzed within the frame work of the band- to-band electron transitions theory. The thickness of RB films has no influence on absorption and refractive indices in the investigated thickness range and within the experimental error. UV irradiation caused a structural transformation of amorphous pristine film to polycrystalline RB film, which resulted in the decrease of absorption coefficient, energy gap and refractive index. The optical functions and their dependence on UV exposure time were directly calculated from the spectral distribution of dielectric constant. | ||||
| Keywords | ||||
| Rose Bengal; Thin films; UV irradiation; Optical properties; Optical functions | ||||
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