Synthesis and characterization of multicomponent Cu2(FexZn1−x)SnS4 nanocrystals with tunable band gap and structure

Multicomponent chalcogenide Cu2(FexZn1−x)SnS4 nanocrystals were synthesized by a facile solution method. The ratio x of Fe/(Zn + Fe) can be tuned across the entire composition from 0 to 1 by rationally adjusting the Fe/Zn ratio in metal sources. By varying the value of x, the band gap energy of nanocrystals can be readily tuned from 1.25 eV to 1.52 eV. XRD analysis indicates the structure transition from stannite to kesterite may occur at x = 0.4 for Cu2(FexZn1−x)SnS4. In addition, photo-electrical conversion performance can be improved by partly substituting Zn with Fe in Cu2ZnSnS4.