Some Photophysical Properties of Electronically Excited Phenyldibenzophosphole in Rigid Polymer Matrices

Abstract

Phenyldibenzophosphole (PDP), present as a dopant in polymer matrices, has been subjected to photoexcitation by 308 nm excimer laser pulses. Both polystyrene (PS) and poly(butyl methacrylate) (PBuMA) have been used as hosts. Luminescence spectra and transient absorption spectra and their respective temporal behavior have been recorded for samples varying in PDP content from 2 to 15% by weight. The time regime from several tens of nanoseconds to seconds was investigated. Phosphorescence decays examined at 15 K yield a lifetime component in the microsecond domain as well as a very long-lived component on the order of seconds. In addition to the phosphorescence spectrum, with origin at 427 nm, a shorter wavelength component with origin near 350 nm is found. In polymer hosts a band at 395 nm is also observed. This latter is assigned to delayed excimer fluorescence while the 350 nm component is delayed monomeric fluorescence. Similarly, an emission at 500 nm is found which grows relative to the main phosphores...