Structural stability of diffusion barriers in thermoelectric SbTe: From first-principles calculations to experimental results

This study involved developing robust diffusion barrier for n-type antimony telluride (SbTe) thermoelectric devices. Compared to conventional Ni barrier, the mid-band metals of Ta and TaN with favored ohmic-like contact exhibited smaller diffusion tail because of structurally stable interface on SbTe, which have been supported by first-principles calculations and demonstrated by experimental results. Furthermore, the TaN barrier has strong ionic Ta-N bonding and a high total energy of -4.7 eV/atom that could effectively suppress the formation of SbTe-compounds interfacial layer.