Defects in Kesterite Type Compounds: Analysis Based on the Results of Transport Investigations

Abstract

Interest to the Cu-based kesterite type compounds, as Cu2ZnSnS4 (CZTS) and related materials, is connected to their promising photovoltaic properties, permitting to regard them as a new generation of materials for solar cells, containing mainly low-cost, low-toxic and abundant components. Experimental investigations of their electronic transport during the last decade, including resistivity and magnetoresistance, permitted to collect important data on the electronic properties of these materials. Among them is the concentration of acceptors, connected to the CuZn antisites. In this work, we propose a model to analyze the concentration of such defects, capable to yield interesting information on other types of defects in kesterites. A detailed analysis based on this model is performed in Cu2Zn1–xCdxSnS4, Cu2ZnSnxGe1–xS4, and Cu2ZnGeSe4 single crystals, as well as in CZTS powders and thin films. The data on such defects as Zn atoms outside the Zn sublattice, on the SnZn and GeZn antisites, as well as on the vacancies in the Zn sublattice, have been obtained.