<s>[INST] Hence, the key to obtain good fluorescence properties is to prepare the CZTS material with ideal stoichiometry. The Zn:Cu ratio, Sn:S ratio and other elements’ ratios with S are important factors to achieve ideal stoichiometry of the CZTS material. The availability of the ZnS phase in the CZTS sample is also a significant factor. Which sentence describes the conditions to achieve ideal stoichiometry of the CZTS material?[/INST]