Accession Number:

ADP012158

Title:

Effects of Sulfur Concentration on the Electron Field Emission Properties of Nanocrystalline Carbon Thin Films

Descriptive Note:

Proceedings

Corporate Author:

PUERTO RICO UNIV SAN JUAN DEPT OF PHYSICS

Report Date:

2001-04-01

Pagination or Media Count:

6.0

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 CH4H2 and hydrogen sulfide-hydrogen H2SH2 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 Vmicrometer 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 Ec and sulfur concentration was found. These finding are attributed to defect induced states within the electronic band structure.

Subject Categories:

  • Physical Chemistry
  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE