Mechanical Properties and Piezoresistivity of Tellurium Nanowires

Among elemental semiconductors, tellurium (Te) exhibits unique mechanical and electromechanical properties due to its highly anisotropic crystal structure and mixed interatomic bonding modes. A lack of experimental investigations of these properties inhibits its adoption in new applications both in bulk form as well as at the nanoscale. In this study, uniaxial tensile tests were conducted in a scanning electron microscope (SEM) on [0001] orientated Te nanowires (NWs) with diameters ranging from 15 to 35 nm. An average elastic modulus is estimated to be 38.6 +/- 4.7 GPa. Both elastic and elastic-plastic behaviors are observed in tested NWs, with a large fracture strain of up to 18% achieved in the latter case. Regardless of the deformation type, electromechanical tests of Te NWs show a trend of decreasing resistance with increasing strain at low-to-moderate tensile strains (0-4%). This piezoresistive effect provides for new opportunities for tellurium to be utilized either in nanoscale devices or in systems that can utilize the extraordinary properties of single-crystal tellurium.