Enhanced electronic transport properties of Te roll-like nanostructures

Abstract

In this work, the electronic transport properties of Te roll-like nanostructures were investigated in a broad temperature range by fabricating single nanostructure back gated field-effect-transistors by photolithography. These one-dimensional nanostructures, with a unique roll-like morphology, were produced by a facile synthesis and extensively studied by scanning and transmission electron microscopy. The nanostructures are made of pure and crystalline Tellurium with trigonal structure (t-Te), and exhibit a p-type conductivity with enhanced field-effect hole mobility between 273 cm2/Vs at 320 K and 881 cm2/Vs at low 5 K. The thermal ionization of shallow acceptors, with small ionization energy between 2 and 4 meV, leads to free hole conduction at high temperatures. The free hole mobility follows a negative power law temperature behavior, with an exponent between -1.28 and -1.42, indicating strong phonon scattering in this temperature range. At lower temperatures, the electronic conduction is dominated by Nearest-Neighbor Hopping (NNH) conduction in the acceptors' band, with a small activation energy ENNH ~ 0.6 meV and acceptors concentration of NA ~ 1x1016 cm-3. These results demonstrate the enhanced electrical properties of these nanostructures, with a small disorder, and superior quality for nanodevice applications.