Three-phase electric power driven electoluminescent devices.

Current power supply networks across the world are mostly based on three-phase electrical systems as an efficient and economical way for generation, transmission and distribution of electricity. Now, many electrically driven devices are relying on direct current or single-phase alternating current power supply that complicates utilization of three-phase power supply by requiring additional elements and costly switching mechanisms in the circuits. For example, light-emitting devices, which are now widely used for displays, solid-state lighting etc. typically operate with direct current power sources, although single-phase alternating current driven light-emitting devices have also gained significant attention in the recent years. Yet, light-emitting devices directly driven by a three-phase electric power has never been reported before. Benefiting from our precious work on coplanar electrodes structured light-emitting devices, in this article we demonstrate proof of a concept that light-emitting components can be driven by three-phase electric power without utilizing intricate back-end circuits and can compose state detection sensors and pixel units in a single device inspiring from three primary colors. Here we report a three-phase electric power driven electroluminescent devices fabricated featuring of flexibility and multi-functions. The design consists of three coplanar electrodes with dielectric layer(s) and light emission layer(s) coated on a top of input electrodes. It does not require transparent electrodes for electrical input and the light emission occurs when the top light-emitting layers are connected through a polar bridge. We demonstrate some applications of our three-phase electric power driven electroluminescent devices to realize pixel units, interactive rewritable displays and optical-output sensors. Furthermore, we also demonstrate the applicability of three-phase electrical power source to drive organic light-emitting devices with red, green and blue-emitting pixels and have shown high luminance (up to 6601 cd/m2) and current efficiency (up to 16.2 cd/A) from fabricated three-phase organic light-emitting devices. This novel geometry and driving method for electroluminescent devices is scalable and can be utilized even in a wider range of other types of light-emitting devices and special units.