CuInSe_2 Formation from CuSe/In_2Se_3 and Cu_2Se/In_2Se_3 Powders: Reaction Kinetics and Mechanisms

摘要

CuInSe_2 (CIS) powders were synthesized using CuSe, Cu_2Se, and In_2Se_3 as the raw materials. The formation mechanisms and reaction kinetics from CuSe/In_2Se_3 and Cu_2Se/In_2Se_3 powders in a selenium atmosphere were investigated. It was observed that the formation temperature of α-CIS powders synthesized using Cu_2Se/In_2Se_3 as the raw materials was higher than that using CuSe/In_2Se_3. Both reactions for Cu_2Se/ In_2Se_3 and CuSe/In_2Se_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_2Se_3 phase was observed. The particle size and morphology of the newly formed CIS was similar to In_2Se_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_2Se_3 surface, assisting CIS formation.