Inkjet Printing and Instant Chemical Transformation of a CH3NH3PbI3/Nanocarbon Electrode and Interface for Planar Perovskite Solar Cells

Abstract

A planar perovskite solar cell that incorporates a nanocarbon hole-extraction layer is demonstrated for the first time by an inkjet printing technique with a precisely controlled pattern and interface. By designing the carbon plus CH₃NH₃I ink to transform PbI₂ in situ to CH₃NH₃PbI₃, an interpenetrating seamless interface between the CH₃NH₃PbI₃ active layer and the carbon hole-extraction electrode was instantly constructed, with a markedly reduced charge recombination compared to that with the carbon ink alone. As a result, a considerably higher power conversion efficiency up to 11.60 % was delivered by the corresponding solar cell. This method provides a major step towards the fabrication of low-cost, large-scale, metal-electrode-free but still highly efficient perovskite solar cells.