As reported recently in the journal Nanotechnology, researchers from National Taiwan University have come up with a convenient and low-cost way of fabricating ZnO/organic heterostructure white-light emitting devices. The team uses a hydrothermal method with a modified seeding layer to grow a ZnO nanorod (NR) array on a polyfluorene (PF) thin film, forming a p-n junction heterostructure.

Enhanced emission

The group's white-light emitting device exhibits a broad emission band covering the entire visible range from 400 to 800 nm. The white-light electroluminescence is attributed to the greatly enhanced green-yellow emission associated with the ZnO surface defects in the ZnO NR array/PF heterostructure and the blue emission from the PF. The enhancement of the ZnO-defect emission is caused by the presence of Zn(OH)2 at the interface between the ZnO NRs and the PF layer.

The study highlights that ZnO nanorod array/PF heterostructures offer a straightforward approach to making white-light electroluminescence devices that take advantage of the high carrier mobility of inorganic materials and the high luminescence efficiency of organic materials at very low cost.