Impact of plasma nanostructuring on the electrical properties of Cu(In,Ga)Se 2 films

Abstract

In this work, the impact of the plasma treatment, during the formation of nanostructure arrays on the surface of the Cu(In,Ga)Se2 films on glass substrates, on the conductivity of the films both in the lateral direction and in the direction normal to the substrate surface was studied. The initial Cu(In,Ga)Se2 films with the Ga/(In + Ga) ratio in the range of 0.03–0.12 were obtained by thermal selenization process of stacked metallic precursors and by co-evaporation of all elements from various sources. The plasma treatment was carried out in a high-density low-pressure RF inductively coupled plasma reactor in argon plasma. The average ion energy was 200 eV, the processing time was 60 s. It is shown that the processes of the plasma nanostructuring of the Cu(In,Ga)Se2 film surface lead to the formation of a thin modified near-surface layer with a resistivity of 2–3 orders of magnitude less than for the bulk of the film.