The conductivity and electrophysical characteristics of Janus-like TaSi2/Si nanoparticles

Abstract

Abstract All applications of single nanoparticles as independent nano-objects are based not on their collective properties, but on their individual properties, which are currently insufficiently studied in the vast majority of cases. The same applies to single Janus-like TaSi2/i-Si nanoparticles, which are independent nano-objects with prominent individual properties. In this regard, a system of single Janus-like TaSi2/i-Si nano-particles with a seven percent weight content of the TaSi2 metal phase is investigated for the first time using atomic force microscopy methods, conductivity, static volt–ampere characteristics (VACs) and the spatial 3D structure of the electrostatics, namely: the thermal emissions and tunneling mechanisms responsible for current transfer through the close-contact area between TaSi2 and i-Si; the effect of a serial resistance of RS = 156 MΩ on the VACs, the barriers ϕbm ( f) = 0.578 eV and ϕbm (r) = 0.648 eV, large values of the ideality indices nf = 3.61 and nr = 5.07 for the VAC reverse and forward branches; the 3D distribution of the electrostatic potential of the surface 4.84 ⩽ Ф(x,y)⩽ 4.90 eV; the electrostatic field | E | = 1.76 × 106 V m−1, and the capacitive contrast ∂C(x, y)/∂z. The values of ϕbm , which are uncharacteristic for commonly used metal/Si Schottky contacts, and the abnormally large values of n and RS confirm the pronounced individual properties of these nanoparticles. The presence of a potential barrier in the close TaSi2/i-Si contact leads to the emergence of a space charge region with a sufficiently strong intrinsic electric field E. The latter contributes to the redistribution of electric charges and the appearance of an electric dipole moment in the particles, which increases the number of their degrees of freedom. All these individual features strongly influence the adhesion and transport properties of the particles and their interactions with electromagnetic radiation, which are of particular interest to specialists in the fields of semiconductor electronics, microwave engineering, nanomechanical systems, catalysis, and biomedicine.