Enhanced thermoelectric properties of bismuth telluride films with in-plane and out-of-plane well-ordered microstructures

The n-type Bi2Te3 films with well-ordered microstructures were deposited on SiO2/Si substrates by unbalanced magnetron sputtering (UBMS) technique. Fully compact oriented films were obtained around RT and 400 K. The (001) textured films with both in-plane and out-of-plane ordering were fabricated successfully. The in plane ordering consists of high density of low-angle grain boundaries, which results in notable increase of the electrical conductivity and the improvement in thermoelectric properties from RT to 473 K. The growth mechanism is discussed in terms of the fundamental principles of UBMS comprehensively, demonstrating an efficient approach to tailoring well-ordered Bi2Te3-based alloys with enhanced thermoelectric performance. (C) 2016 Elsevier Ltd. All rights reserved.