Fabrication and electrical characterization of circuits based on individual tin oxide nanowires

Abstract

Two- and four-probe electrical measurements on individual tin oxide (SnO(2)) nanowires were performed to evaluate their conductivity and contact resistance. Electrical contacts between the nanowires and the microelectrodes were achieved with the help of an electron- and ion-beam-assisted direct-write nanolithography process. High contact resistance values and the nonlinear current-bias (I-V) characteristics of some of these devices observed in two-probe measurements can be explained by the existence of back-to-back Schottky barriers arising from the platinum-nanowire contacts. The nanoscale devices described herein were characterized using impedance spectroscopy, enabling the development of an equivalent circuit. The proposed methodology of nanocontacting and measurements can be easily applied to other nanowires and nanometre-sized materials.

Electrical and optical properties of spin-coated SnO2 nanofilms

“…In literature one could find a commonly accepted opinion that the RC model of a tin dioxide sensor consists of three cascaded circuits [21][22][23][24][25]. The first circuit consists of a resistance only.…”

“…The third circuit known from the literature consists of a resistance and a constant phase element (CPE). Impedance of a CPE is equal to 1/(j·ω n ), where n varies depending on the sensor, from 0.74 [23] to 0.97 [25]. In the literature, there is a consensus that this circuit describes the dynamics of the transport and accumulation of charge on single crystal grain boundaries, in particular, on the border of nanowires.…”

Electrical properties of individual tin oxide nanowires contacted to platinum electrodes

“…2͒, which can be explained considering the existence of two back-to-back Schottky barriers connected in series to both extremes of the nanowires. 17 Conduction through these devices is dominated by reversebiased junctions and, therefore, it is the major contribution to the total contact resistance ͑Fig. 3͒.…”

1∕f noise of SnO2 nanowire transistors

“…[4][5][6][7] SnO 2 with a tetragonal crystal structure ͑lattice parameters a = 4.737 Å and c = 3.185 Å͒ is an excellent candidate for novel electronic devices thanks to the wide band gap of 3.6 eV and a high surface-to-volume ratio. 8,9 Applications include integrating high-performance TFTs, flexible and transparent NWTs, and gas sensors. [4][5][6][7] However, in order to optimize transistor performance even further, it is important to understand the NW transport characteristics and to control the semiconductordielectric interface properties in these NW-based devices.…”