Co-sensitization of TiO2 by PbS quantum dots and dye N719 in dye-sensitized solar cells

Abstract

PbS quantum dots (QDs) were prepared by an in-situ chemical bath deposition method, where the QD size is manipulated by adjusting the dipping time in the respective Pb2+ and S2- ion solutions. They are characterized by using XPS and UV-visible absorption. The photovoltaic performances of the dye-sensitized solar cells constructed from PbS-sensitized TiO2, N719-sensitized TiO2 and co-sensitized TiO 2 have been evaluated. PbS QDs are shown to elevate the open circuit voltage (Voc) and consequently increase the efficiency from 5.95% by N719-sensitized TiO2, to 6.35%, by the co-sensitized TiO2. The operating mechanism involved in the co-sensitization is presented and discussed. © 2010 Elsevier B.V.