Photoelectric and photorefractive properties of composites based on poly(vinylcarbazole) and ruthenium(II) tetra-15-crown-5 phthalocyanine with axially coordinated pyrazine molecules

摘要

The photoelectric and photorefractive characteristics of composites based on poly(vinylcarbazole) containing crown-substituted ruthenium phthalocyanine with axially coordinated pyrazine molecules, (R _4Pc)Ru(pyz) _2 (where R _4Pc ~2- is [4,5,4',5',4'',5'',4''', 5'''-tetrakis-(1,4,7,10,13-pentaoxatridecamethylene)phthalocyanine ion], pyz is pyrazine), have been studied. Supramolecular ensembles of these complexes are responsible for optical absorption and photoelectric and photorefractive sensitivity in the near IR region. It has been found that under the action of a 1064-nm laser, the quantum efficiency of formation of mobile charge carriers, estimated from the photocurrent, corresponds to the Onsager equation when the quantum yield of formation of thermalized electron-hole pairs φ 0 = 0.35 and the separation distance is 9.8 ?, irrespective of the (R _4Pc)Ru(pyz) _2 content. The kinetic curves of amplification of the information laser beam are bellshaped. This suggests that the photorefractive characteristics are underestimated owing to lowering to zero of the field E0 inside the layer as a result of buildup of space charge in the near-electrode space upon passing the dark current. The two-beam gain coefficient at an (R _4Pc)Ru(pyz) _2 content of 7 wt % is Γ = 62 cm ~(-1) as estimated from the maximum of the bell-shaped curve.