Controlling the diameter of aligned single-walled carbon nanotubes on quartz via catalyst reduction time

• Verfasst von: Schweiger, Kai Manuel [VerfasserIn]
• Verfasst von: Schaudig, Maximilian [VerfasserIn]
• Verfasst von: Gannott, Florentina [VerfasserIn]
• Verfasst von: Killian, Manuela Sonja [VerfasserIn]
• Verfasst von: Bitzek, Erik [VerfasserIn]
• Verfasst von: Schmuki, Patrik [VerfasserIn]
• Verfasst von: Zaumseil, Jana [VerfasserIn]
• Titel: Controlling the diameter of aligned single-walled carbon nanotubes on quartz via catalyst reduction time
• Verf.angabe: Manuel Schweiger, Maximilian Schaudig, Florentina Gannott, Manuela S. Killian, Erik Bitzek, Patrik Schmuki, Jana Zaumseil
• E-Jahr: 2015
• Jahr: 21 August 2015
• Umfang: 8 S.
• Fussnoten: Gesehen am 22.07.2020
• Titel Quelle: Enthalten in: Carbon
• Ort Quelle: Amsterdam [u.a.] : Elsevier Science, 1963
• Jahr Quelle: 2015
• Band/Heft Quelle: 95(2015), Seite 452-459
• ISSN Quelle: 1873-3891
• DOI: doi:10.1016/j.carbon.2015.08.058
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1725272822

Abstract

One of the main objectives of chemical vapor deposition (CVD) growth of single-walled carbon nanotubes (SWCNT) is control over their diameter and type (metallic or semiconducting). Here, we investigate the evolution of iron catalyst particles on quartz substrates depending on the duration of the reduction step with hydrogen and its effect on the growth of horizontally aligned SWCNT. We find a strong dependence of catalyst particle size and size distribution on the initial iron film thickness and the reduction time at 630 °C. Initial decrease of the particle size is followed by an unexpected increase. Statistical analysis of the Raman radial breathing modes of the SWCNT over large areas gave reliable and reproducible diameter distributions that correlated directly with the catalyst particle size distributions. By changing the reduction time it was possible to reproducibly shift the average SWCNT diameter from 1.5 (±0.3) nm to 1.2 (±0.2) nm while maintaining a nanotube density of 5-6 SWCNT/μm. In order to describe the evolution of the particle size during the reduction process at this particular temperature, we propose a model that includes the diffusion of iron into the quartz and its re-emergence.