PHOTOELECTRICAL PROPERTIES OF INDANDIONE CHROMOPHORE IN SOLID STATE

The optically induced switching of electrical properties of indandione type molecules, which consist of acceptor and donor groups, are investigated. Both calculation and experimental results show a reversible highly dipolar photoinduced intramolecular electron transfer in 2-(4'-N, N-dimethylaminobenzyliden)indan-1,3-dione molecule (DMABI). Kelvin's probe technique is applied to investigate the surface potential of a host-guest polymer film with four different DMABI derivatives. The derivatives have been chosen to compare the influence of the geometry, concentration and dipole moment of a molecule in the ground and excited states on the response time and amplitude of photoinduced surface potential. It is shown that the time of fast response (up to several seconds) to irradiation is independent of the concentration of molecules in a polymer film. Dependence of the amplitudes of photoinduced changes in the surface potential on the molecules concentration is observed for DMABI and its three derivatives. The optimal concentration of guest molecules in the polymer matrix is in the range 10-25 wt% (depending on the molecule).