Various approaches to white organic light emitting diodes and their recent advancements

This article provides a brief overview of the recent progress in white organic light emitting diodes (WOLEDs) that are considered to be the low-cost alternatives for solid-state illumination purposes. The article concentrates on various device designs and the underlying physical processes that govern the white-light creation. The operating principles and the problems associated with each device design are discussed. The emphasis is on identifying various approaches to achieve WOLEDs and their review based on publications appearing in the last two years.