ABSTRACT
This chapter describes the relation between the photophysical and photochemical properties and charge transfer (CT) interaction in aromatic polyimides. As known widely, polyimides (PI) are usually prepared upon thermal dehydration (imidization) of polyamic acid (PAA). CT complex formation gives rise to the appearance of a new absorption band different from that of each component often in the visible range. Most of the studies on the electronic spectra of PIs have been concerned with Kapton film until recently, because it was first developed as a high-performance PI film. In general, since CT complexes participate in the carrier generation required for photocurrent, aromatic polyimides are expected to have photoconductivity higher than other common polymers. The action spectrum of the photocurrent in PI(pyromellitic acid dianhydride (PMDA)/oxydianiline (ODA)) film showed two bands peaking at 350 nm and 460 nm. These bands correspond roughly to the excitation spectrum of the intermolecular CT fluorescence. This suggests that the intermolecular CT interaction participates in the photocurrent phenomenon.
