Quantized conductance in SnO2 nanobelts with rectangular hard-walls

TL;DR

This paper reports the observation of quantized conductance in SnO2 nanobelts at low temperatures, demonstrating quantum confinement effects and electron subband filling in a novel nanostructure.

Contribution

It introduces the first experimental evidence of quantized conductance in SnO2 nanobelts modeled as quantum wires with rectangular hard-walls.

Findings

Quantized conductance observed as current oscillations at low temperatures.

Oscillations disappear above 60K, indicating temperature dependence.

Subband separation matches theoretical predictions.

Abstract

Quantized conductance is reported in high-crystalline tin oxide (SnO2) nanobelt back-gate field-effect transistors, at low temperatures. The quantized conductance was observed as current oscillations in the drain current vs. gate voltage characteristics, and were analyzed considering the nanobelt as a quantum wire with rectangular cross-section hard-walls. The quantum confinement in the nanowires created conditions for the successive filling of the electron energy-subbands, as the gate voltage increases. When the source-drain voltage is changed the oscillations are not dislocated with respect to Vg, indicating flat-band subband energies at low temperatures. The subband separation was found to be in good agreement with the experimental observations, since the oscillations tend to disappear for T > 60K. Therefore, a novel quantum effect is reported in SnO2 nanobelts, which is expected to behave as bulk at zero electric gate fields.