Magnesium doped ZnO nanostructures synthesis using citrus aurantifolia extracts: Structural and field electron emission properties

We report here the field electron emission performance of pure ZnO and Mg doped ZnO nanostructures prepared on aluminium substrates using Citrus Aurantifolia by the sol-gel method. XRD analysis confirmed that the pure ZnO and Mg-doped ZnO nanostructures were polycrystalline with the hexagonal wurtzite crystal structure. Based on EDX analysis, the Mg atomic percentage incorporated in the ZnO samples increased with increasing Mg concentration during synthesis. With Mg doping, the field electron emission performance was significantly affected possibly due to increase in electrical conductivity with doping level. The turn-on electric field values for ZnO nanostructures decreased as dopant concentration increased with values of 6.99, 6.35, 6.07 and 5.99 V/mu m for pure ZnO, and 3, 5, and 10 mol% Mg-doped ZnO nanostructures respectively. Almost similar trend was observed for the threshold electric field values of 9.16, 9.17, 8.62 and 8.49 V/mu m for pure ZnO, and 3, 5, and 10 mol% Mg-doped ZnO nanostructures, respectively. Field enhancement factor, beta, showed no significant trend and was comparable for all samples mainly due to the similar geometrical features of the samples. Emission currents up to a few mAs and with good stability obtained with Mg doping are potentially applicable in field emission technology.