A study of energy transfer processes in zinc–porphyrin films using Monte Carlo simulation of fluorescence decay

Abstract Energy transfer in thin films of zinc tetra(-octylphenyl)-porphyrin (ZnTOPP) doped with the copper (CuTOPP) or free-base (H 2 TOPP) analogues were investigated by time-resolved fluorescence and Monte Carlo simulations, applied to a single domain model of parallel porphyrin stacks. Rate constants for intra- and inter-stack energy transfer are (0.8–1.1)×10 12 and (71–91)×10 9 s −1 , respectively. The fluorescence lifetimes for ZnTOPP and H 2 TOPP films are (1.80–1.88)×10 −9 and (6.8–7.3)×10 −9 s. The rate constant for H 2 TOPP to ZnTOPP back transfer is (8.8–9.4)×10 6 s −1 . The results agree with those of a previous analytical analysis [1] .