Facile surfactant-free synthesis of p-type SnSe nanoplates with exceptional thermoelectric power factors

Abstract

A surfactant-free solution methodology, simply using water as a solvent, has been developed for the straightforward synthesis of single-phase orthorhombic SnSe nanoplates in gram quantities. Individual nanoplates are composed of {100} surfaces with {011} edge facets. Hot-pressed nanostructured compacts (Eg ∼ 0.85 eV) exhibit excellent electrical conductivity and thermoelectric power factors (S2σ) at 550 K. S2σ values are 8-fold higher than equivalent materials prepared using citric acid as a structure-directing agent and electrical properties are comparable to the best performing extrinsically-doped p-type polycrystalline tin selenides. The method offers an energy-efficient, rapid route both to p-type and n-type SnSe nanostructures.