Self-Assembled ZnO Nanostructure for Field-Emission Devices

Zinc oxide (ZnO) nanorods on Au patterned Si substrates were fabricated using vapor transport method. The XRD pattern showed the ZnO nanorods were highly c-axis oriented similar to ZnO thin films. The photoluminescence spectrum at 77 K of ZnO nanorods was consisting of the fundamental near band edge emission of ZnO in the UV region along with a broad defect induced emission around green band. The field emission properties of the nanorods showed a current density of 1mA/cm2 at an applied field of 10V/m, which is comparable to other reported values of ZnO nanorods. The patterned gold island formed by self-assembly of polystyrene ball on Si substrate acted as a catalyst in the growth of nanorods as well as stable ohmic contact for field emission.