Table 1. Stoichiometric Composition of Precursor Solutions for All Ge–Sn Compositions.

	SnCl2·H2O [M]	GeCl2·dioxane [M]	total [M]
Cu2ZnSnS4	0.160		0.160
Cu2ZnSn0.8Ge0.2S4	0.128	0.032	0.160
Cu2ZnSn0.6Ge0.4S4	0.096	0.064	0.160
Cu2ZnSn0.5Ge0.5S4	0.080	0.080	0.160
Cu2ZnSn0.3Ge0.7S4	0.048	0.112	0.160
Cu2ZnGeS4		0.160	0.160