KF post deposition treatment in co-evaporated Cu(In,Ga)Se2 thin film solar cells: Beneficial or detrimental effect induced by the absorber characteristics

Thomas Lepetit, Sylvie Harel, Ludovic Arzel, Guy Ouvrard, Nicolas Barreau

Index: 10.1002/pip.2924

Full Text: HTML

Abstract

To improve the photovoltaic performance of Cu(In,Ga)Se2-based solar cells by the use of a potassium fluoride post-deposition treatment (KF-PDT), the surface of the absorber, grown on soda lime glass by 3-stage co-evaporation, has to be copper depleted. Then, KF-PDT induces the formation of an indium selenide layer containing K and prevents the segregation of elemental selenium and copper selenide. The Ga depletion after KF-PDT is due to the formation of GaF3 removed during the subsequent chemical bath deposition of CdS.