Large Enhancement of Field Emission from ZnO Nanocone Arrays via Patterning Process

We report on the direct observation of enhanced field emissions from patterned ZnO nanocones compared with the plain geometry of ZnO nanocones For the unambiguous comparison of field emissions from patterned nanocones and plain(nonpatterned) nanocones periodic arrays of ZnO nanowires were fabricated on Si by photolithography RCA 1(aq) solution etching and the hydrothermal growth method The conelike morphology formation was achieved by anisotropic etching on the different crystal planes of ZnO nanowires in an aqueous solution of acetic acid [CH3COOH(aq)] As the control sample of plane ZnO nanocones the ZnO nanowires with a plain geometry were synthesized under the same conditions as the patterned sample The field emission measurements on the plain ZnO nanocones and patterned ZnO nanocones reveal that the turn on field decreases from 6 0 V/mu m (plane nanocone arrays) to 3 8V/mu m (patterned nanocone arrays) (C) 2010 The Japan Society of Applied Physics