Electron emission from SrTiO3-coated silicon-tip arrays

The field emission of electrons from silicon-tip arrays coated with SrTiO3 thin layers has been, investigated. It is found that the emission properties are sensitive to the preparation conditions and the extent of nitrogen doping in the magnetron sputtering. Nitrogen addition could reduce the band gap of the SrTiO3 caps to improve the emission properties significantly with a threshold field of 17 V/mu m and the stability of emitted current compared with the uncoated silicon tips. Results demonstrate that SrTiO3 thin films with N addition effectively lower the work function of silicon tips. However, oxygen-rich SrTiO3 exhibits a detrimental effect. Findings are explained in terms of valence-density-state modification by the nonbonding lone pairs and the lone-pair-induced dipoles [W. T. Zheng. and C. Q. Sun,,Prog. Solid State Chem. 34, 1 (2006)]. (c) 2007 American Vacuum Society.