Ultrahigh In-Plane Thermoelectric Performance in Self-Assembled PbSe:Au Films With Vertically Aligned Nanopillar

Abstract

Self-assembled nanocomposites with tunable physical properties have potential applications in advanced devices. In this work, self-assembled PbSe:Au films with vertically aligned nanopillars (VAN) were fabricated by pulsed laser deposition. Detailed heterostructures with atomic-resolution have been investigated by cross-sectional scanning tunnelling microscopy. The results show that self-assembled Au nanopillars in a PbSe matrix is realized. Compared with PbSe matrix, PbSe:Au vertical interface can facilitate energy filter effect and lower the in-plane thermal conductivity. The maximum ZT values for n-type self-assembled VAN film is ~2.6 at 523 K, which is ~400% higher than that of pure PbSe film (ZT=0.5). This study suggests that the vertical interface in the unique VAN provide a viable route to manipulate the thermoelectric properties for the thermoelectric materials.