title: Thermoluminescence and photoluminescence analyses of MEH-PPV, MDMO-PPV and RU(bpy)3 gamma-irradiated polymer thin films.
abstract: Effects of irradiation with (60)Co gamma photons on poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), poly[2-methoxy-5-(3',7' dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) and tris(2,2'-bipyridyl)dichlororuthenium(II) hexahydrate (Ru(bpy)3) thin films were analyzed regarding their thermoluminescence (TL) and photoluminescence (PL) properties. A linear TL dose response was obtained from the MEH-PPV and MDMO-PPV polymer films in dose ranges of approximately 0.170-4.08kGy and 0.170-0.850kGy, respectively, followed by a supralinear behavior. A dependence on the conjugation length of the polymer chains which was favored by heating of the film, was observed, and irradiation generated a blue-shift in MEH-PPV and Ru(bpy)3. Furthermore, the PL structure was not modified. The most likely effect involved in the TL emission was trapping. The high activation energy values of the traps in the TL may be attributed in part to the binding energy of the exciton. A deconvolution process was carried out to obtain the kinetic parameters from the TL glow curves and PL spectra.
authors.affiliation: Unidad Profesional Interdisciplinaria de Ingeniería y Tecnologías Avanzadas, IPN, Av. Instituto Politécnico Nacional 2580, Col. La Laguna Ticoman, 07340 México D.F., México; Unidad de Irradiación y Seguridad Radiológica, Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, A.P. 70-543, 04510 México D.F., México.
authors.forename: A
authors.initials: A
authors.lastname: Ortiz-Morales
authors.affiliation: Escuela Superior de Física y Matemáticas, IPN, Av. Instituto Politécnico Nacional s/n, Col. San Pedro Zacatenco, 07738 México D.F., México.
authors.forename: J
authors.initials: J
authors.lastname: Ortiz-Lopez
authors.affiliation: Unidad de Irradiación y Seguridad Radiológica, Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, A.P. 70-543, 04510 México D.F., México. Electronic address: ecruz@nucleares.unam.mx.
authors.forename: E
authors.initials: E
authors.lastname: Cruz-Zaragoza
authors.affiliation: Unidad Profesional Interdisciplinaria de Ingeniería y Tecnologías Avanzadas, IPN, Av. Instituto Politécnico Nacional 2580, Col. La Laguna Ticoman, 07340 México D.F., México. Electronic address: rgomeza@ipn.mx.
authors.forename: R
authors.initials: R
authors.lastname: Gómez-Aguilar
keywords: Dosimetric material; Kinetic property; Radiation effects; Thermoluminescence