Behavior of the discrete energy states

A study comparing composite thermally stimulated current (TSC) curves that usually are measured by the single heating method, and partial curves from repeated heating and cooling processes, is reported. For this purpose, both the auto-separation (As) and reconstruction (Re) methods are necessary. The former enables us to separate accurately composite curves obtained by one heating process into several TSC curves with a single relaxation process. The latter enables us to reconstruct TSC curves from partial curves obtained by repeated heating and cooling, even if they had no observed peak. Both methods apply a theory, using the fundamental element that was defined originally to be the smallest quantity and a coordinate determined arbitrarily on the measured TSC curves. The current type of charge compensation equation that makes accurate RC procedure possible was first proposed. From detailed analysis, it was confirmed that an electron trap and a hole trap are produced simultaneously in a naphthacene doped anthracene single crystal. Analysis suggests that repeated heating and cooling influences both trap sites and that the indirect transport mechanisms via discrete state-to-state charge transfer processes is not negligible.