Energy transfer in the photoluminescence of poly(3-thiophene acetic acid)-poly(vinyl alcohol) blends

We have investigated the optical properties of polymeric blend poly(3-thiophene acetic acid)-poly(vinyl alcohol). We have observed two band sets with different features in the photoluminescence spectrum. One set shows a band peak at 560 nm and the other shows two band peaks at 670 and 710 nm. We have analyzed the polarization and temperature dependence of photoluminescence spectrum. We have observed that the first set is unpolarized and shows weak temperature dependence, while the second one shows strong temperature dependence and a polarized band at 710 nm. These results were interpreted as evidence of energy transfer associated with migration and trapping of excitons in the poly(3-thiophene acetic acid) chains using a kinetic model with we estimated the energy of the trap site for the triplet exciton emissions.