Dresden 2017 – wissenschaftliches Programm
HL 4.4: Topical Talk
Montag, 20. März 2017, 11:00–11:30, CHE 89
Inhomogeneities in chalcopyrites for solar cells — •Daniel Abou-Ras — Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
Thin-film solar cells with polycrystalline Cu(In,Ga)(S,Se)2 absorber layers have exhibited record conversion efficiencies of up to 22.6%. Although parallel to the substrate, the concentrations of the matrix elements in these Cu(In,Ga)(S,Se)2 thin films do not vary substantially, obvious inhomogeneities are the [In]/[Ga] and also (in case S is present) [S]/[Se] gradients perpendicular to the substrate. Moreover, also indications for various net doping concentrations in neighboring grains have been reported, which may be explained by locally varying point-defect concentrations. On the (sub)nanometer scale, compositional variations at different line and planar defects in Cu(In,Ga)(S,Se)2 thin films have been detected. The present contribution will give an overview of all these imhomogeneities existing on different length scales, but all affecting the potential landscape of chalcopyrite-type Cu(In,Ga)(S,Se)2 absorber layers.