Document Details Document Type : Article In Journal  Document Title : Estimation of the Dispersion and Absorption Parameters of تعيين معاملات الامتصاص والتشتت لشرائح رقيقة من فيثالوسيانين الماغنيسيوم   Subject : Physics  Document Language : English  Abstract : Magnesium phthalocyanine MgPc thin films are prepared at room temperature by thermal evaporation technique. The spectral absorption parameters are determined by applying the molecular orbital theory but the other optical parameters are deduced using band model consideration. The optical constants n and k are evaluated using spectrophotometric measurements of transmittance and reflectance at nearly normal incidence of light in the wavelength range 190-2500 nm. The absorption spectrum recorded in the UV-VIS region shows two absorption bands of phthalocyanine molecule, namely the Soret band (B) and the Q-band. The Q-band shows its characteristic splitting (Davydov splitting), and ?Q is 0.17 eV. The absence of a distinct peak near 4.27 eV in MgPc could be due to the absence of d electrons of the Mg atoms. The analysis of the spectral behaviour of the absorption coefficient in the absorption region near fundamental edge reveal indirect transitions. The fundamental and the onset energy gaps could also be estimated as 2.73 ? 0.01eV and 1.40 ? 0.15 eV, respectively, for the as deposited films. From analysis of dispersion curves, the dielectric constants and other dispersion parameters are also obtained. All previous parameters are obtained for as deposited and annealed films at 350oC for two hours. Discussion of the obtained results and comparison with the previously published data are also given.  ISSN : 1319-1012  Journal Name : Journal of King Abdulaziz University - science  Volume : 21  Issue Number : 2  Publishing Year : 2009 AH 2009 AD  Article Type : Article  Added Date : Monday, February 1, 2010  Researchers Researcher Name (Arabic) Researcher Name (English) Researcher Type Dr Grade Email عادل صالح فيدة Faidah, Adel S Researcher Doctorate afaidah@kau.edu.sa Files File Name Type Description  24995.pdf pdf Abstract Back To Researches Page