Phase Selectivity of Copper Sulfide: Synthesis and Application

High-purity copper sulfides including CuS, Cu 1.75 S and Cu 2 S were synthesized using an easy and controllable two-step heating method in a mixed solution of ethylene glycol and triethylenetetramine. Petal-like CuS, near-spherical Cu 2 S, and regular hexagonal Cu 1.75 S were obtained by simply changing the solvent volume ratio (SVR) of the mixed solution, i.e. the phase of the products solely determined by the SVR of the solution. The influence of the solvent on the final products as well as the reaction mechanism of the system were investigated and discussed. The approach is rapid, easily scalable, and environmentally friendly. As a preliminary application demonstration, dye-sensitized solar cells were assembled using the as-synthesized copper sulfides and photoelectric conversion efficiencies up to 3.62% were achieved.