Control of carrier concentration in SnS films by annealing with S and Sn

Abstract

The carrier properties of thermally evaporated SnS films were examined by electrical resistivity and thermopower measurements. The SnS films were annealed at 300 °C with constituent elements such as S powder and Sn films in order to control carrier concentration. The S- or Sn-annealed SnS films exhibit optical bandgaps of 1.2–1.36 eV, electrical resistivities of 0.25–5.4 × 103 Ωcm, activation energies of 0.15–0.2 eV, and Seebeck coefficients of 0.8–2.7 mV K−1. The changes of electrical resistivity and Seebeck coefficient were observed for SnS films by annealing with S and Sn. These results indicate that annealing treatments with S and Sn cause changes of carrier concentration in SnS films. Thermopower measurement is useful for the carrier evaluation of semiconducting SnS films.