title: Ultrathin nondoped emissive layers for efficient and simple monochrome and white organic light-emitting diodes.
abstract: In this paper, highly efficient and simple monochrome blue, green, orange, and red organic light emitting diodes (OLEDs) based on ultrathin nondoped emissive layers (EMLs) have been reported. The ultrathin nondoped EML was constructed by introducing a 0.1 nm thin layer of pure phosphorescent dyes between a hole transporting layer and an electron transporting layer. The maximum external quantum efficiencies (EQEs) reached 17.1%, 20.9%, 17.3%, and 19.2% for blue, green, orange, and red monochrome OLEDs, respectively, indicating the universality of the ultrathin nondoped EML for most phosphorescent dyes. On the basis of this, simple white OLED structures are also demonstrated. The demonstrated complementary blue/orange, three primary blue/green/red, and four color blue/green/orange/red white OLEDs show high efficiency and good white emission, indicating the advantage of ultrathin nondoped EMLs on constructing simple and efficient white OLEDs.
authors: State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate University of the Chinese Academy of Sciences, Changchun 130022, People's Republic of China.
authors: Yongbiao
authors: Y
authors: Zhao
authors: Jiangshan
authors: J
authors: Chen
authors: Dongge
authors: D
authors: Ma