PHOTOLUMINESCENCE STUDY IN PHOTOOXIDATION OF POLY(PHENYLMETHYLSILANE) FILMS

Temporal variations of photoluminescence (PL) in poly(phenylmethylsilane) (PPMS) films under the irradiation with 325nm light at room temperature in air have been investigated. The PL intensity from the sigma*-sigma transition shows a temporal decay fitting to a straight line in a log-log plot, where its slope switches from small one (-0.2) to steep one (approximately -1) at a certain time. This transfer time corresponds to the time when the PL intensity of a 530 nm peak (ascribable to the pi*-sigma transition) begins to decrease and increses proportionally with increasing the molecular weight of PMMS in the range less than 2.2x10(5). The decay properties are discussed by introducing a thermal activated process into the photooxidation.