Electronic structure and total-energy calculations were performed for CuInSe2 and Cu(In,Ga)Se2 using density-functional theory with generalized gradient corrections. To understand the fracture and deformation behavior in chalcopyrites, the cleavage and generalized stacking fault energies in CuInSe2 and Cu(In,Ga)Se2 were calculated, and the brittle character of the crack propagation was demonstrated. Antiphase boundary and intrinsic stacking fault defects had low formation energies and were quite probable in these chalcopyrites. The main slip system and preferable cleavage plane should be <¯110>(112) and (112), respectively. For the <110>(001) and <¯110>(112) dislocations in CuInSe2, a strong tendency for splitting in two partials was predicted.

First-Principles Study of Deformation Behavior and Structural Defects in CuInSe2 and Cu(In,Ga)Se2. N.I.Medvedeva, E.V.Shalaeva, M.V.Kuznetsov, M.V.Yakushev Physical Review B, 2006, 73[3], 035207 (6pp)