High-efficiency, low-drive-voltage, semitransparent stacked organic light-emitting device

Abstract
We report a semitransparent, two-color, stacked organic light-emitting device (SOLED) with high efficiency, low drive voltage, and minimal color distortion. The SOLED emits light from both device surfaces. The external quantum efficiencies of the green and red stacked elements are 1% and 0.4%, respectively, where only the photons emitted from the substrate surface are collected. The drive voltage for the top stack element is decreased to ∼12 V by using a modified indium tin oxide thin film deposition process. Color distortion and angular dependence of the emission spectra are minimal.