Anomalous charge-voltage (Q-V) characteristics are observed for several types of alternating-current thin-film electroluminescent (ACTFEL) devices. These Q-V curves are anomalous because conduction charge flows in these devices exclusively during the portion of the wave form in which the applied voltage is constant, at its maximum value; this kind of conduction charge is denoted relaxation charge. In a normal ACTFEL device, most of the conduction charge flows during the portion of the wave form in which the applied voltage increases with time. The anomalous Q-V characteristics are attributed to insulator leakage for the devices tested. Simulation shows that such anomalous behavior may arise from either insulator of phosphor leakage
