Field Emission Properties and Reliability of ZnO Nanorod, Nanopagoda, and Nanotip Current Emitters

Fabrication, optical, and field emission properties of ZnO nanorod, nanopagoda, and nanotip emitters were studied. The ZnO nanotip emitters are prepared by using combination of solution method and oxygen plasma treatment. All the emitters exhibit a highly c-axis preferred orientation crystalline structure. The nanopagoda and nanotip emitters have turn-on fields of 1.43 and 1.07 V/mu m, respectively, under 1 mu A/cm(2) and field enhancement factors of 3681 and 4735 at 25 degrees C, respectively. The nanotip emitters with tip angle of 20 degrees and number density of 10 emitters/mu m(2) have very stable emission at 25 degrees C over 2 x 10(4) s and successive operation between the 25 degrees C and 100 degrees C over 5000 s. Our finding provides an effective route for practical applications in flat panel display and light-emitting device in the future.