Enhanced field emission properties of α-Fe2O3 nanostructures with the removal of adsorbed gas molecules

Abstract

Quasi-1D α-Fe2O3 nanostructure arrays of four different morphologies (random nanoflakes, random nanobelts, quasi-aligned nanostrips and quasi-aligned nanoneedles) were successfully synthesized via a simple heating process. Field emission measurements indicate that the α-Fe2O3 nanoneedle arrays are superior field emitter exhibiting low turn-on voltage, high current density, and large field-enhancement factor due to better vertical alignment and higher aspect ratio. In addition, we found that adsorbed oxygen molecules greatly hindered the field emission performance of the nanostructures. Prolonged field emission process could drive the oxygen molecules away and give rise to markedly improved and efficient α-Fe2O3 nanostructures field emitter. The improved field emission is attributed to desorption of the oxygen molecules during the field emission process. © 2011 American Chemical Society.