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 to p-type SnSe nanostructures. A surfactant-free aqueous solution methodology has been developed for the straightforward synthesis of SnSe nanoplates in gram quantities. These nanoplates can be hot-pressed into nanostructured compacts with much higher thermoelectric power factors than surfactant-prepared products and comparable values to bulk polycrystalline counterparts.