Electric field induced fluorescence quenching and photocarrier generation in x -metal-free phthalocyanine

The electric field induced fluorescence quenching and transient photoconductive response of x-H2Pc particles dispersed in an inert polymer matrix have been measured for different applied electric fields and temperatures between 22 and 70 °C. The results of the measurements show that fluorescence quenching and carrier generation are the different aspects of the same process, namely, the depopulation of the first excited singlet state by exciton dissociaton into electron hole pairs. The linear correlation between fluorescence quenching and relative photoresponse enables the determination of absolute quantum efficiency by performing only relative measurements. The temperature dependent studies showed consistency between carrier generation and fluorescence quenching, and established an activation energy for the generation of charge carriers.