Electron Injection Dynamics of Perylene Derivatives into ZnO and TiO2 Particle Films

The electron injection dynamics of two perylene dyes bound to ZnO and TiO2nanoparticles was investigated with femtosecond transient absorption simultaneously monitoring the rise of the cationic and the decay of the excited state. Electron transfer from the chromophores was slower when attached to ZnO compared to TiO2. The excited state decay and the cationic state rise showed very good agreement at early times, indicating direct electron injection into the conduction band for both semiconductors in absence of intermediate states.