Field Emission Properties of CNTs Prepared from Ferrocene and Camphor Precursors by One-Step TCVD Method

Carbon nanotubes (CNTs) have important application value in terahertz electron sources. A simple one-step thermal chemical vapor deposition (TCVD) method is proposed to synthesize large-area (1 cm2) CNTs directly on silicon substrates by pyrolyzing ferrocene alone and its mixture with camphor. The optimal ferrocene content for fabricating superior CNT emitters was determined to be around 20% with smallest diameter, moderate length, relatively lower defect density, and uniform and vertical alignment, achieving the lowest turn-on field (10 μA/cm2) and threshold field (1 mA/cm2) values of 0.8 V/μm and 2.23 V/μm, along with a field enhancement factor of 27433 and a maximum current density of 6.49 mA/cm2 at 4.85 V/μm. The proposed fabrication method is safe, cost effective, and highly reproducible, making it a promising technique for large-area high-quality field emission cold cathode applications.