Compositional gradients and impurity distributions in CuInSe2 thin-film solar cells studied by atom probe tomography

The present study is about the characterization of CuInSe2 thin-film solar cells using atom probe tomography. Elemental distributions, in particular compositional gradients and impurity segregation at internal interfaces, have been determined at the sub-nanometer scale. Direct evidence of impurity (Cd, Na, and O) segregation at CuInSe2 grain boundaries is given. Possibly occurring point defects are discussed with respect to their influence on the electronic properties and the efficiency of the solar cells. Copyright (C) 2012 John Wiley & Sons, Ltd.