Electrically-detected and optically-detected magnetic resonance for organic semiconductor devices

Abstract

In the operation process of an organic semiconductor device represented by an organic LED (OLED), it is generally assumed that electron-hole pairs are generated as an intermediate state between carriers and excitons, which play a major role in current and light emission, respectively. However, since probing techniques for electron-hole pairs have not been established, the behavior of the pair during the semiconductor operation has not been clarified. In this paper, we show that electron spin resonance (ESR) measurements via recording current and emission intensity are effective for selection probes of electron-hole pairs. These techniques are expected to provide new information on the operation process of devices through non-destructive measurement of the operating state.