Kesterite / wurtzite Cu2ZnSnS4 nanocrystals: Synthesis and characterization for PV applications

Wet chemical synthesis and characterizations of quaternary chalcogenide Cu
2
ZnSnS
4
(CZTS) nanocrystals, as an alternative solar absorber material to conventional quaternary CuInxGa
(1−x)
S2 (CIGS), is given in detailed. Dodecanethiol and oleylamine are used as hot organic solvents and capping ligands, as for oleic acid is used with dodecanethiol to control the nanocrystals morphology. Two kinds of metal precursors ae used: metal chlorides and metal acetate as precursors of Cu, Zn and Sn, respectively, while elemental sulfur is used as sulfur source. The effect of dodecanethiol and oleylamine on the final phase of the CZTS nanocrystals is studied. The as-synthesized (CZTS) nanocrystals are characterized by X-ray diffraction (XRD), Raman spectroscopy, and Transmission electron microscopy (TEM). Our results showed that CZTS nanocrystals can be obtained with different crystallographic phases, kesterite and wurtzite structures. Furthermore, we found that the CZTS nanocrystals structure can be controlled as kesterite phase or wurtzite phase using dodecanethiol-sulfur solution and oleic acid instead of oleylamine during the synthetic procedure.