ZnO-NWs/Cu-based metallic glass nanotube array (ZNWs/Cu-MeNTA) for field emission properties

●The first study for the field emission properties of the ZnO-NWs/Cu-based Metallic Glass Nanotube Array nanostructures.●To analyze the effects of annealing treatment on the field emission properties.●The FED properties might be due to the trade-off between the enhanced crystallization and the amounts of the ZNWs break down. [Display omitted] The field emission properties of a novel ZnO-NWs/Cu-based metallic glass nanotube array (ZNWs/Cu-MeNTA) heterostructure are studied. A sample is annealed at 300 °C for 1 h at atmospheric pressure in a tube furnace as post-treatment. The turn-on electric field Eon (at a current density of 0.1 μA/cm2) and corresponding field enhancement factors β for the as deposited and 300 °C annealed ZNWs/Cu-MeNTA are respectively 1.47 V/μm, 13,042 and 1.77 V/μm, 10,954. The increase on the turn on field might be due to oxidation of the as-deposited ZNWs/Cu-MeNTA after the thermal post-treatment. Crystallization is enhanced after the field emission measurements, but parts of the ZnO-NWs break down. The Eon increases (1.29–1.47 V/μm) in the successive field emission measurements for the as-deposited ZNWs/Cu-MeNTA. In addition, the Eon decreases (2.26–1.77 V/μm) for the 300 °C annealed thermal post treatment ZNWs/Cu-MeNTA. This phenomenon might be due to the trade-off between the enhanced crystallization and the amounts of the ZnO-NWs break down, respectively causing a decrease and increase in the turn on field. This novel nanostructure for field emission studies might be useful for use in future mini-display device, optoelectronics, sensors, piezoelectric-nanogenerator, solar cells and battery applications.