Abstract
To study the time-resolved photo luminescence of the physical systems like quantum dots and conjugated polymers, we set up the system of time correlated single photon counting, it is applied to study the carrier transport, electron-hole recombination and mobility in conjugated polymer related systems. We use the system to measure the emission mechanism of conjugated polymer material, PFO, doped with different concentration of Iridium complex, (Btp)2Ir. We find that the higher concentration of Iridium complex is, the stronger phosphorescence intensity is observed. As a result, there is longer triplet emission lifetime. Therefore, we reason that there is more energy transferring to Iridium. On the contrary, when we decrease the concentration of Iridium complex, phosphorescence intensity get weak such that the fluorescence of PFO dominated the emission. Consequently, we get the shorter triplet emission lifetime. In addition, we use the system to measure 5% Iridium complex doped PFO to investigate the relation between lifetime and temperature, and find that the lifetime is independent of temperature .This result is not consistent with other measurements by frequency-dependent methods taken in our laboratory. Further investigation is needed to resolve the discrepancy.