The energetics of vacancies in CuInSe2 were calculated by using a hybrid functional HSE06 (HSE = Heyd - Scuseria - Ernzerhof), which gave a better description of the band-gap as compared to (semi)local exchange-correlation functionals. It was shown that , contrary to current beliefs, copper and indium vacancies induce no defect levels within the band gap and therefore could not account for any experimentally observed levels. The selenium vacancy was responsible for only one level, namely, a deep acceptor level ε(0/2-). A strong preference was found for VCu and VSe over VIn under practically all chemical conditions.

Vacancies in CuInSe2: New Insights from Hybrid-Functional Calculations. L.E.Oikkonen, M.G.Ganchenkova, A.P.Seitsonen, R.M.Nieminen: Journal of Physics - Condensed Matter, 2011, 23[42], 422202