ABSTRACT
There are four types of EL devices: ac thin film, ac powder, dc thin film, and dc powder. The ac thinfilm display is by far the dominant device type. Some liquid crystal displays use ac powder EL for backlights. There is currently little or no commercial application of dc EL devices, either thin film or powder [1]. The focus here is on ac thin-film EL (ACTFEL) devices. While there are no widely established standard measurement techniques for the other EL device types, measurements similar to those described herein for ACTFEL devices could be applied with appropriate modifications to the other methods of device excitation.
