کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1484883 1510528 2008 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Optical studies of aromatic polyazomethine thin films
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Optical studies of aromatic polyazomethine thin films
چکیده انگلیسی

Optical transmission and fundamental reflectivity spectra of aromatic polyazomethine thin films, obtained by vacuum evaporation via the polycondensation process have been investigated in the wide spectral range 0.49–6.2 eV. As initial monomers, terephaldehyde (TPA) and one of four different amines, i.e. paraphenylene-diamine (PPDA), 7,2-diamino-fluorene, 1,1′-biphenyl-3,3′,4,4′-tetramine and 3-amino-4-(1-naphthyldiazenyl)phenylamine (fat brown RR) have been used, respectively. Amorphous character of these films was confirmed by the results of X-ray diffraction and AFM investigations. Absorption coefficient of the films has been obtained and the edge of absorption seems to be similar to the absorption edge typical for amorphous semiconductors, what allowed to obtain the Urbach energy and ET parameter. The energy gaps of the films, following the Tauc relation, are found to change from 2.05 to 2.4 eV, depending on the length of conjugated part of the polymer chain. Absorption bands above the absorption edge, observed for different polyazomethine films are connected with their chemical structure and possible electronic transitions.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Non-Crystalline Solids - Volume 354, Issues 10–11, 1 February 2008, Pages 856–862
نویسندگان
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