Ultrahigh in-plane thermoelectric performance in self-assembled PbSe:Au films with vertically aligned nanopillars

Abstract

Self-assembled nanocomposites with tunable physical properties have potential applications in advanced devices. In this work, we fabricated self-assembled PbSe:Au films with vertically aligned nanopillars (VANs) by pulsed laser deposition. We used scanning tunneling microscopy to evaluate detailed heterostructures at atomic resolution. The results indicate that we prepared self-assembled Au nanopillars in a PbSe matrix. Compared with the PbSe matrix, the PbSe:Au vertical interface can facilitate the energy-filter effect and lower the in-plane thermal conductivity. The maximum ZT values for an n-type self-assembled VAN film is ∼2.6 at 523 K, which is ∼520% higher than that of a pure PbSe film (ZT = 0.5). This study suggests that the vertical interface in the unique VAN described here provides a viable route to manipulate the thermoelectric properties of thermoelectric materials.