Insight into the Interfacial Elastic Contact in Stacking Perovskite Solar Cells

Stacking perovskite solar cells (PSCs) are emerging cells with two detached electrodes during fabrication process, in which the crucial step is the intimate mechanical and electronic contact between the laminated parts. The interfacial elastic contact of stacking PSCs with four different p-type organic semiconductors has been systematically studied. Studies confirm that poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is an elastic interface material with excellent performance. The convex-concave morphology of PEDOT:PSS surface and the interfacial elastic deformation make a contribution to a desirable conductive contact between two electrodes with sufficient contact area, thereby providing a highly reliable connection and efficient charge transport channel between the semi-cells. Based on conducting polymer PEDOT:PSS, planar-structured stacking PSCs are fabricated exhibiting power conversion efficiency of 13.49% with 1.0 cm(2) area. Connecting electrodes with excellent conductivity and elasticity are also proved to be essential to the flexible assembly and readily detachment.