Synthesis and size control of CIS powder by the addition of diethylamine in the mechanochemical method

CIS powder has been highly researched as a material for thick-film photovoltaic cells. CIS can be mass produced and synthesized through the mechanochemical method. Despite the simple process, however, the mechanochemical method has been reported to pose a problem with respect to uniformity as it is difficult to control the particle size and there are remnants of unreacted reactants after synthesis. Thus, in this study, diethylamine was added during the synthesis of CIS powder using the mechanochemical method to control particle size and remove excess reactants to obtain uniform powder. An increase of diethylamine during CIS synthesis led to an enhanced wet milling effect, which in turn decreased the powder size. However, at 22.5 wt.% and above, the mechanochemical energy was insufficient for synthesis, resulting in an observation of the raw materials, In, Se and a small amount of CuSe, without the synthesis of CIS.