Fabrication[edit]
CZTS has been prepared by a variety of vacuum and non-vacuum techniques. They mostly mirror what has been successful with CIGS, although the optimal fabrication conditions may differ. Methods can be broadly categorized as vacuum deposition vs. non-vacuum and single-step vs. sulfization/selenization reaction methods. Vacuum-based methods are dominant in the current CIGS industry, but in the past decade there has been increasing interest and progress in non-vacuum processes owing to their potential lower capital costs and flexibility to coat large areas.
A particular challenge for fabrication of CZTS and related alloys is the volatility of certain elements (Zn and SnS) which can evaporate under reaction conditions. Once CZTS is formed, element volatility is less of a problem but even then CZTS will decompose into binary and ternary compounds in vacuum at temperatures above 500 °C. This volatility and difficulty of preparing a single-phase material has resulted in the success of many traditional vacuum methods. Currently the best CZTS devices have been achieved through certain chemical methods which allow CZTS formation at low temperatures avoiding volatility problems.
A continuous flow process using ethylene glycol as a solvent has been developed at Oregon State University which may be suitable for industrial scale mass