Stark spectroscopy of CuPc organic semiconductor with a submicron metal-electrode grating

摘要

The optical and electro-optical properties of organic copper phthalocyanine semiconductor (alpha- CuPc) have been investigated by Stark (electroabsorption) spectroscopy using a metal electrode grating with a submicron (0.88 mu m) interelectrode distance. Differences between dipole moments (Delta mu) and polarizabilities (Delta alpha) in the excited and ground states of alpha-CuPc are measured for a nanoscale semiconductor film. It is concluded that the extremely high values of Delta mu and Delta alpha are in principle not parameters of individual alpha-CuPc molecules: they are determined by exciton effects specifically in the polycrystalline medium with a characteristic morphology of hyperfine films, which depends on the structure of the samples and their fabrication technology.