Alternate heteroepitaxial growth of chloroindium phthalocyanine and chloroaluminum phthalocyanine ultrathin multilayered structure and its xerographic and optical properties

Abstract

(ClInPc/ClAlPcCl) n ultrathin multilayered structures and co-deposited ClInPc–ClAlPcCl composite films were prepared by a high-vacuum organic-beam deposition technique. The Q-band absorption is shifted with changes in the period number and layer thickness. With a decrease in the period number, the energy splitting of the Q-band increased up to the maximum value and then decreased. The changes in optical absorption spectra of the ultrathin multilayered structures are most likely to be due to the dipole–dipole and charge transfer interaction among the different molecular assemblies. The photosensitivity of the ultrathin multilayered structures is over 10-fold better than that of the co-deposited composite film. The improvement in xerographic properties is probably due to the fact that an ultrafast photo-induced charge transfer and separation can be generated from the interfacial potential barrier of (ClInPc/ClAlPcCl) n structures and the photogenerated holes can be swept out due to tunneling prior to recombination. The performance of these ultrathin multilayered structures makes them an efficient building block for organic photoelectronic devices.