All-solution-processed fabrication of electroluminescent devices with stacked blue, green and red quantum dot layers

Over the past few years the performance of colloidal quantum dot-light-emitting diode (QLED) has been progressively improved. However, most of QLED work has been fulfilled in the form of monochromatic device, while full-color-capable white QLED still remains nearly unexplored. Using red, green, and blue quantum dots (QDs), herein, we for the first time demonstrate all-solution-processed fabrication of full-color QLED with an RGB-QD stacked structure. The interlayer mixing-free formation of such stacked RGB emitting layer is enabled by applying a buffer layer of ZnO nanoparticles located at the interfaces between different-colored QD layers, which effectively prevents the underlying QD layer from being damaged upon solution-processing the following another QD layer.