Effects of Sulfur Concentration on the Electron Field Emission Properties of Nanocrystalline Carbon Thin Films
Abstract
The electron field emission properties of sulfur-assisted nanocrystalline carbon (n-C: S) thin films grown on molybdenum substrates by hot-filament CVD technique using methane-hydrogen (CH(4)/H(2)) and hydrogen sulfide-hydrogen (H(2)S/H(2)) gas mixtures were investigated. The field emission properties of the S-assisted films are reported as a function of sulfur concentration. The incorporation of S caused structural and microstructural changes that were characterized with SEM, AFM and Raman spectroscopy (RS). The S-assisted films show smoother surfaces and smaller grains than those grown without. The lowest turn-on field measured was around 4.5 - 5.0 V/micrometer films grown with 500 ppm of hydrogen sulfide and at 900 degrees C. The electron field emission properties of S-assisted films were also compared to those grown without sulfur (i.e., intrinsic). An inverse correlation between the threshold field (E(c)) and sulfur concentration was found. These finding are attributed to defect induced states within the electronic band structure.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2001
- Accession Number
- ADP012158
Entities
People
- B. L. Weiss
- B. R. Weiner
- G. Morell
- Salil Gupta
Organizations
- University of Puerto Rico