Mg-doped ZnO nanostructures for efficient Organic Light Emitting Diode

Abstract ZnO and Mg-doped ZnO nanostructures have been synthesized by a hydrothermal method for its potential application in Organic Light Emitting Diodes (OLED). Studies have been undertaken for structural as well as optical properties of ZnO after Mg doping with various concentrations. Field Emission Scanning Electron Microscopy with Energy-dispersive X-ray analysis reveals the morphology and chemical composition of nanostructures shows the formation of ZnO rod-like structure which, interestingly, converted into the multi-pod structure with Mg doping. X-ray diffraction reveals the hexagonal phase of the wurtzite structure of ZnO. UV–Visible absorption spectroscopy suggests the exciton characteristic, at room temperature, with band gap variation while Photoluminescence spectra reveal emission in two different spectral regions (ultraviolet and blue). Synthesized materials have been blended with Poly [9, 9-dioctylfluorenyl-2, 7-diyl] (PFO) and prototype OLED has been fabricated using these materials as an emissive layer. An electroluminescence spectrum shows prominent blue emission at 433 nm, 460 nm, and 490 nm at 6 V. Current-Voltage (I-V) characteristics indicate that the OLED device with 10% Mg doping in ZnO is most stable compared to others.