Influence of UV Irradiation, Annealing, and Structure of the Terminal Units on the Photoluminescence Spectra of Poly(diphenylene phthalide) Films

Abstract

The photoluminescence (PL) method has been used to study the change in the PL spectra of poly(diphenylene phthalide) (PDP) films under the influence of such factors as the wavelength of the exciting light, the duration of exposure to UV light, and annealing. The contribution to the change in the PL spectra of pretreatment of the samples and the structure of the terminal units of the polymer chain has been estimated. The recombination mechanism of experimentally observed processes in PDP films upon UV irradiation and annealing is discussed. These processes include, in particular, the processes of transformation of the lateral and defective fragments of polymer chains, and the reasons for the appearance of the long-wavelength emission band and the change in the ratio of the intensities of the emission bands with maximums at 344 and ~500 nm.