Femtosecond laser pulses are employed to study the dynamics of the absorption spectra of fluoro-aluminium phthalocyanine polycrystalline thin films. Following excitation by 620 nm pulses into the first electronic transition a very rapid energy relaxation of the excitons is observed within the 55 fs duration of the pump pulse. Following this process two extremely fast decay routes lead to the recovery of the ground state: exciton-exciton annihilation with an intensity-dependent decay of 550 fs at power density of 1.2 GW/cm2 and exciton-phonon coupling with a 4 ps decay time.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Condensed Matter Physics
- Atomic and Molecular Physics, and Optics
- Surfaces and Interfaces