Low-field electron emission from tetrapod-like ZnO nanostructures synthesized by rapid evaporation

Tetrapod-like zinc oxide (ZnO) nanostructures can be synthesized by rapid heating metal zinc pellet at 900 degreesC under air ambient. Catalyst, vacuum, and carrying gas are not necessary, and more importantly, it is a volcanic process for rapid and mass production. The turn-on field of the synthesized tetrapod-like ZnO nanostructures is found to be as low as 1.6 V/mum at the current density of 1 muA/cm(2). These ZnO nanostructures are technologically useful for vacuum electron devices because they can be easily and economically synthesized and deposited on large substrates. (C) 2003 American Institute of Physics.