Energy transfer between Langmuir–Blodgett monolayers of organic dyes

The Langmuir–Blodgett technique has been used to prepare multilayer structures in order to investigate the distance dependence of the nonradiative transfer of electronic energy from a donor plane of molecules to an acceptor plane. The distance between well-separated donor molecules and acceptor molecules was carefully controlled by spacer layers of arachidic acid. New systems for energy transfer studies are considered that use N-hexyl-N′-ethyl-3,4:9,10-perylenetetracarboxyldiimide (HPTCDE) and N-hexyl-3,4:9,10-perylenetetracarboxylmonoimide (HPTCO) as donors and lutetium diphthalocyanine (LuPc2) as acceptor. The limitations of the Förster dipole theory of energy transfer from a donor monolayer of point dipoles to an acceptor layer are discussed. Key words: energy transfer, Langmuir–Blodgett, diphthalocyanine, perylene.