Facile synthesis of ultrafine Cu2ZnSnS4 nanocrystals by hydrothermal method for use in solar cells

We introduce a hydrothermal method for synthesizing ultrafine earth abundant Cu2ZnSnS4 (CZTS) nanocrystals with an average size of 5–6 nm using simple Cu(II), Zn(II), Sn(II) inorganic salt and thiourea as precursor. X-ray diffraction, Raman spectrum and transmission electron microscopy studies indicate that CZTS nanocrystals with pure kesterite structure have been synthesized at temperature as low as 180 °C. The band-gap energy determined from the absorbance spectrum is 1.47 eV, suggesting that as-synthesized CZTS nanocrystals are very suitable for photovoltaic applications.

► We developed a hydrothermal method for synthesizing ultrafine Cu2ZnSnS4 nanocrystals.
► The as synthesized CZTS nanocrystals have an average size of ~ 5 nm.
► The band-gap energy determined from the absorbance spectrum is 1.47 eV.
► The CZTS nanocrystals are suitable to be used to fabricate CZTS ‘ink’-based solar cells.