Tailoring electronic properties of SnO$_2$ nanobelts via thermal annealing

Metal oxide semiconductors nanowires are a viable option for the fabrication of transistors with desirable characteristics for nanoelectronic and sensing applications. SnO$_2$ nanobelts (NBs) have been synthesized using catalyst-free chemical vapor deposition. The growth parameters have been explored, producing NBs as long as millimeters. These NBs have been demonstrated as effective channel-limited gas [1], pH [2] and protein [3] field-effect transistor (FET) sensors. Through modification of O$_2$ and vacuum thermal annealing conditions, we investigate the control and optimization of the electronic properties of the NBs to achieve desired device characteristics for biosensing applications. A pronounced increase in conductance, up to the order of microsiemens, has been observed in annealed NBs under O$_2$ environment at elevated temperatures above 600$^\circ$C. We also examine the properties of the electrical contacts with different metallization and varying NB conductivity. Optimal device characteristics for various sensing applications will be tested and discussed.\\[4pt] [1] L.L. Fields et al., Appl. Phys. Lett. 88, 263102 (2006).\\[0pt] [2] Yi Cheng et al., Nano Lett. 8, 4179–4184 (2008).\\[0pt] [3] Yi Cheng et al., Biosensors and Bioelectronics 26, 4538-4544 (2011).