A general strategy for synthesis of quaternary semiconductor Cu2MSnS4 (M = Co2+, Fe2+, Ni2+, Mn2+) nanocrystals

Abstract

Quaternary semiconductor Cu₂MSnS₄ (M = Co²⁺, Fe²⁺, Ni²⁺, Mn²⁺) nanocrystals have been successfully synthesized via a simple and mild solvothermal method. Cu₂FeSnS₄ and Cu₂CoSnS₄ show a spherical shape; Cu₂NiSnS₄ and Cu₂MnSnS₄ possess a nail-like structure and a rod-like structure. The four types of nanocrystals exhibit significantly different magnetic properties. Cu₂FeSnS₄ and Cu₂CoSnS₄ nanoparticles show ferromagnetic behavior; Cu₂MnSnS₄ and Cu₂NiSnS₄ nanorods exhibit superparamagnetic behavior at low temperature. The band gaps of Cu₂MSnS₄ (M = Co, Fe, Ni, Mn) nanocrystals are in the range of 1.2–1.5 eV, indicating a high potential application in low-cost thin film solar cells.