Lei, BoRyu, KoungminDe-Arco, Lewis GomezHan, SongBadmaev, AlexanderFarmer, DamonKim, KevinGordon, RoyWang, Kang L.Zhou, Chongwu2017-08-082010Lei, Bo, Koungmin Ryu, Lewis Gomez De-Arco, Song Han, Alexander Badmaev, Damon Farmer, Kevin Kim, Roy Gordon, Kang L. Wang, and Chongwu Zhou. 2010. “Raman Characterization and Polarity Tuning of Aligned Single-Walled Carbon Nanotubes on Quartz.” Japanese Journal of Applied Physics 49 (2) (February 22): 02BC02. doi:10.1143/jjap.49.02bc02.0021-4922http://nrs.harvard.edu/urn-3:HUL.InstRepos:33724761Raman characterization has been employed to study key features of highly aligned single-walled carbon nanotubes grown on quartz substrates. The nanotubes are observed to possess an estimated metallic/semiconducting ratio of 1:2.7, and Raman spectra also confirm the high integrity of nanotubes before and after being transferred from quartz to Si/SiO2 substrates. Based on the as-grown and the transferred aligned nanotubes, we have further fabricated top- and back-gated nanotube devices, respectively. The top-gated transistors exhibit ambipolar transport characteristics with high transconductance, small subthreshold swing of 110 mV/decade and on/off ratio of 107, while the back-gated transistors show unipolar p-type characteristics. Furthermore, we have demonstrated polarity tuning to produce both predominately n- and p-type top-gated carbon nanotube transistors by controlling the polarity of gate voltage during electrical breakdown, which has great potential for building complementary carbon nanotube circuits.en-USJournal Article10.1143/JJAP.49.02BC02