Surface oxidation and thermoelectric properties of indium-doped tin telluride nanowires

Abstract

The recent discovery of excellent thermoelectric properties and topological surface states in SnTe-based compounds has attracted extensive attention in various research areas. Indium doped SnTe is of particular interest because, depending on the doping level, it can either generate resonant states in the bulk valence band leading to enhanced thermoelectric properties, or induce superconductivity that coexists with topological states. Here we report on the vapor deposition of In-doped SnTe nanowires and the study of their surface oxidation and thermoelectric properties. The nanowire growth is assisted by Au catalysts, and their morphologies vary as a function of substrate position and temperature. Transmission electron microscopy characterization reveals the formation of amorphous surface in single crystalline nanowires. X-ray photoelectron spectroscopy studies suggest that the nanowire surface is composed of In2O3, SnO2, Te and TeO2 which can be readily removed by argon ion sputtering. Exposure of the cleaned nanowires to atmosphere yields rapid oxidation of the surface within only one minute. Characterizations of electrical conductivity σ, thermopower S, and thermal conductivity \k{appa} were performed on the same In-doped nanowire which shows suppressed σ and \k{appa} but enhanced S yielding an improved thermoelectric figure of merit ZT than the undoped SnTe.

arXiv commentSubstantial revisions; accepted for publication in Nanoscale

References in corpus (20)

• Unpaired Majorana fermions in quantum wires
• Topological Crystalline Insulators in the SnTe Material Class
• Experimental realization of a topological crystalline insulator in SnTe
• Topological crystalline insulator states in Pb(1-x)Sn(x)Se
• A topological crystalline insulator (TCI) phase via topological phase transition and crystalline mirror symmetry
• Enhanced Thermoelectric Performance and Anomalous Seebeck Effects in Topological Insulators
• Observation of Dirac node formation and mass acquisition in a topological crystalline insulator
• Unusual nature of fully-gapped superconductivity in In-doped SnTe
• Dirac mass generation from crystal symmetry breaking on the surfaces of topological crystalline insulators
• Enhanced superconducting pairing interaction in indium-doped tin telluride
• Band structure of SnTe studied by Photoemission Spectroscopy
• Mapping the unconventional orbital texture in topological crystalline insulators
• Strain engineering Dirac surface states in heteroepitaxial topological crystalline insulator thin films
• Synthesis of SnTe Nanoplates with {100} and {111} Surfaces
• Fermiology of Strongly Spin-Orbit Coupled Superconductor Sn1-xInxTe and its Implication to Topological Superconductivity
• Optimizing the superconducting transition temperature and upper critical field of Sn(1-x)In(x)Te
• Superconducting properties of the In substituted Topological Crystalline Insulator, SnTe
• Revealing surface states in In-doped SnTe superconducting nanoplates with low bulk mobility
• Synthesis and characterisation of nanomaterials of the topological crystalline insulator SnTe
• Superconducting Sn_{1-x}In_{x}Te Nanoplates