Understanding and improving carbon nanotube-electrode contact in bottom-contacted nanotube gas sensors
- Journal Article
Suspended carbon nanotube field-effect transistors fabricated with a dry transfer technique demonstrate strong promise as ultra-low-power, hysteresis-free gas sensors. However, the difficulty of establishing a good electrical contact between a nanotube and the electrode surface often limits the yield of low-resistance devices that can operate as low-power gas sensors. In this work, the contact resistance at the nanotube-metal interface and the distribution thereof are reduced significantly by removing the top layer of electrode surface with Ar-ion etching directly before nanotube placement. Combined with post-transfer annealing, this pre-transfer electrode surface cleaning reduces the median ON-resistance of transistors by an order of magnitude--from 1.56 MOhm to 143 kOhm--and the interquartile range by more than two orders of magnitude--from 9.38 MOhm to 59 kOhm. The ability to consistently improve nanotube-metal contact demonstrated in this work is a significant advance in the fabrication of ultraclean nanotube transistors and carbon nanotube gas sensors. Show more
Journal / seriesSensors and Actuators, B: Chemical
Pages / Article No.
SubjectCarbon nanotube-metal contact; Carbon nanotube field-effect transistors; Contact resistance; Self-heating; Nanomaterials
Organisational unit03609 - Hierold, Christofer / Hierold, Christofer
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