Cu(i)-based delafossite compounds as photocathodes in p-type dye-sensitized solar cells

Abstract

The research of p-type dye-sensitized solar cells (p-DSSCs) has attracted growing attention because of the potential for integration with conventional n-type DSSCs (n-DSSCs) into the more efficient tandem-DSSCs. However, to date the performance of p-DSSCs is lagging behind that of n-DSSCs. One main reason is the lack of optimal photocathode materials. This article reviews the most recent progress in utilizing Cu(I)-based delafossite compounds, CuMO₂ (M = Al, Ga or Cr), as photocathodes in p-DSSCs. As alternative materials to the commonly used NiO, the CuMO₂ compounds have their intrinsic advantages such as lower valence band edge, larger optical bandgap and higher conductivity. By providing an insight into these materials and their applications in p-DSSCs, this perspective aims to stimulate more exciting research in the development of p-DSSCs as well as of tandem-DSSCs.