High-performance white organic light-emitting diodes using distributed Bragg reflector by atomic layer deposition

Abstract

White organic light-emitting diodes (WOLEDs) with higher performance, which have enjoyed application in high-quality lighting sources, are here demonstrated with improved optical and electrical properties. The integration of a novel transparent distributed Bragg reflector (DBR), which consists of periodically alternating layers of atomic layer deposition-fabricated ZrO 2 /Zircone films and sputtered tin-doped indium oxide into OLEDs microcavities were studied to obtain four-peak electroluminescence (EL) spectra. Three types of OLEDs with two-peak, three-peak, and four-peak EL spectra have been developed. The results of the two-peak spectra show that the DBR structures have an outstanding effect on carrier capture; as a result, the device exhibits a stronger stability in color at various applied voltages. The Commission Internationale de L'Eclairage (CIE) coordinates of the two-peak device at 5-13 V shows few displacements and a negligible slight variation of (±0.01, ± 0.01). In addition, the four-peak WOLED also yields a high color purity white emission as the luminance changes from 100 cd m -2 to 10,000 cd m -2 .