Characterization and field emission properties of lanthanum monosulfide nanodot and nanowire arrays deposited by pulsed laser deposition on self-assembled nanoporous Al2O3 matrix
Successful growth of Lanthanum Monosulfide (LaS) nanodot and nanowire arrays has been performed by pulsed laser deposition (PLD) using self-assembled nanoporous alumina templates containing pores about 50nm wide and 200-300 nm deep. The arrays were characterized by X-Ray Diffraction, Atomic Force Microscopy (AFM), Field Emission Scanning Electron Microscopy (FE-SEM) and Scanning Anode Field Emission Microscopy (SAFEM). The array of LaS nanodots grows selectively at boundaries between different regions-of the alumina film with local hexagonal symmetry of pores. The density of these dots is about 109/cm (Fig.1). Cross sectional FE-SEM showed that LaS nanowires also grow inside the pores with a density of 1010/cm2, which is equal to the pore density of the templates. The field emission properties of the LaS nanodots grown on top of the alumina templates were measured using SAFEM. A typical current-voltage characteristic is shown in Fig.2. Using the conventional Fowler-Nordheim relation, the work function of the LaS nanodots has been extracted from the slope of the plot ln(J/F2) vs 1/F, where J is the field emission current density and F is the local applied field. This leads to an outstanding, reproducible effective work function value of ～1 eV for the LaS nanodots. The threshold for an emission current density of 1 mA/cm2 occurs around a 150 V/μm which is considerably lower than the 230 V/μm threshold value reported recently for LaS thin films.
M. Cahay L. Grazulis K. Garre V. Semet Vu Thien Binh D.J. Lockwood J.W. Fraser S. Bandyopadhyay S. Pramanik S. Fairchild
ECECS Department, University of Cincinnati, Cincinnati, Ohio 45221 Air Force Research Laboratory, WPAFB, Ohio 45433 Equipe Emission Electronique, LPMCN-CNRS, University Lyon 1, Villeurbanne 69622, France Institute for Microstructural Sciences, National Research Council, Ottawa, Ontario K1A OR6, Canada Department of Electrical Engineering, Virginia Commonwealth University, Richmond, VA 23284
国际会议
桂林
英文
139-140
2006-07-17（万方平台首次上网日期，不代表论文的发表时间）