FEMTOSECOND TIME-RESOLVED OPTICAL-RESPONSE OF PHTHALOCYANINE LANGMUIR-BLODGETT-FILM

The mechanism of 2,9,16,23-tetra-heptadecylamido-substituted vanadyl phthalocyanine Langmuir-Blodgett film was studied with femtosecond laser pulses. After the excitation into the first electronic excited band, an ultrafast decay due to phonon-exciton coupling greatly affected by temperature was observed. Following this process, exciton-exciton annihilation leads to the recovery of the ground state with a decay time of about 10 ps. The Frenkel exciton theory was employed to give a complete interpretation of the dynamics. An even slower relaxation was also observed.Physics, AppliedSCI(E)EI13ARTICLE94648-46517