We report the effects of precursor uniformity on the efficiency of Cu2ZnSnSxSe4 - x (CZTSSe) solar cells using sputtered precursors. The reduction of Sn cluster agglomeration in the Cu/Sn/Zn stacked precursor created synthesis of more uniformly distributed CZTSSe absorbers during the annealing process. The secondary phase difference between the 80 W and 40 W sputtered CZTSSe absorbers was confirmed with Raman analysis at 178 cm(-1) and 259 cm(-1). The 40 W sputtered CZTSSe cell produced blue region enhancement of external quantum efficiency results due to improvement of the pn-junction properties. The CZTSSe 40 W cells achieved a maximum power conversion efficiency of 5.7% and short-circuit current of 32.4 mA/cm(2). (C) 2017 Elsevier B.V. All rights reserved.