CuSbSe2-assisted sintering of CuInSe2 at low temperature

Ternary chalcopyrite-like compound of CuSbSe2 was found to be an excellent agent to assist the reactive sintering of CuInSe2 (CIS) from Cu2Se and In2Se3 at lower temperature, which is the light absorber material in the most promising thin film solar cells. With low melting point and excellent wettability, CuSbSe2 acts as a liquid-phase sintering flux to efficaciously increase atomic diffusion rate during the sintering process, and furthermore the two raw materials provide chemical driving force. By the intentional introduction of CuSbSe2 doping into CuInSe2, the well-crystallized ceramic samples can be perfectly sintered at 500 °C, without obviously scarifying light absorption at the low doping level (≤0.5 mol%). The XPS analyses were performed to determine the crystal lattice location and valence state of Sb. Similar sintering-promoting effect was also found in the CuSbSe2-doped Cu(In,Ga)Se2 (CIGS) film.