“…Therefore, developing colloidal routes, such as spin-casting or printing, to fabricate CIS thin film solar cells that have well controlled stoichiometry, high materials utilization and low processing equipment cost have attracted much attention [3]. CuInSe 2 (CIS) powder has been reported successfully synthesized using solid-state reaction [4][5][6][7][8], solvo-thermal [9][10][11][12], thermolysis [13] and thermal decomposition methods [14][15][16][17]. Compared to the liquid-phase process, the solid state reaction is much easier and cheaper.…”