CuInSe 2 Formation from CuSe / In 2 Se 3 and Cu 2 Se / In 2 Se 3 Powders: Reaction Kinetics and Mechanisms

CuInSe 2 ( CIS ) powders were synthesized using CuSe , Cu 2 Se , and In 2 Se 3 as the raw materials. The formation mechanisms and reaction kinetics from CuSe / In 2 Se 3 and Cu 2 Se / In 2 Se 3 powders in a selenium atmosphere were investigated. It was observed that the formation temperature of α‐ CIS powders synthesized using Cu 2 Se / In 2 Se 3 as the raw materials was higher than that using CuSe / In 2 Se 3 . Both reactions for Cu 2 Se / In 2 Se 3 and CuSe / In 2 Se 3 mixtures follow one‐dimensional diffusion‐controlled reactions with apparent activation energies of 124.3 and 73.2 kJ/mol, respectively. For both mixtures the indium‐rich β‐ CIS phase resulting from Cu + ion diffusion toward the In 2 Se 3 phase was observed. The particle size and morphology of the newly formed CIS was similar to In 2 Se 3 , which indicated that the CIS formation kinetics may be dominated by the diffusion of Cu + ions. The Cu – Se liquid phase resulting from the peritectic decomposition of CuSe 2 and CuSe at a relatively low temperature may promote Cu + diffusion into the In 2 Se 3 surface, assisting CIS formation.