Excellent UV absorption in spin-coated thin films of oleic acid modified zinc oxide nanorods embedded in Polyvinyl alcohol

• Published in: The Journal of physics and chemistry of solids 2012-03, Vol.73 (3), p.396-401
• Main Authors: Sajimol Augustine, M., Jeeju, P.P., Sreevalsa, V.G., Jayalekshmi, S.
• Format: Article
• Language: English
• Subjects: A. Thin films; B. Chemical synthesis; C. X-ray diffraction; D. Optical properties; Emission; Nanorods; Nanostructure; Oleic acid; Polyvinyl alcohols; Spectroscopy; Thin films; White light; Zinc oxide
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/j.jpcs.2011.11.004

The aim of the study is to investigate the optical properties of spin-coated, highly transparent nanocomposite films of oleic acid modified ZnO (Zinc oxide) nanorods embedded in Polyvinyl alcohol (PVA) matrix. Pristine and oleic acid (OA) modified ZnO nanorods have been prepared by wet chemical synthesis and are characterized by X-ray diffraction, FESEM, TEM and FT–IR spectroscopy techniques. The optical properties of ZnO/PVA films are studied using UV–visible absorption and Photoluminescence (PL) spectroscopy. The results show that the optical absorption of the films in the UV region is quite high and more than 95% absorption is observed in films prepared from OA modified ZnO nanorods. The excellent UV absorption at around 300 nm offers prospects of applications of these films as efficient UV filters in this wavelength region. The PL spectrum of pristine ZnO nanorods shows almost white light emission whereas OA modified ZnO nanorods have a more intense peak centered in the blue region. The PL emission of OA modified ZnO/PVA film shows appreciable increase in intensity compared to the film obtained with pristine ZnO. The surface modification of ZnO by the polymer matrix removes defect states within ZnO and facilitates sharp near band edge PL emission at 364 nm. ► Pristine and oleic acid modified ZnO nanorods are prepared by wet chemical method. ► Highly transparent ZnO/PVA thin films are prepared using spin-coating technique. ► Optical studies of the films are done using UV–vis absorption and PL spectroscopy. ► Excellent UV absorbing properties of these films find applications in UV filters.