Improved efficiency of CdS quantum dot sensitized solar cell with an organic redox couple and a polymer counter electrode

Article abstract of DOI:10.1016/j.electacta.2014.06.072

Quantum dot sensitized solar cells (QDSSCs) based on an organic thiolate/disulfide redox couple (C₇H₅N₄S^-/C₁₄H₁₀N₈S₂or C₂H₃N₄S^-/C₄H₆N₈S₂) and a polymer counter electrode [poly (3, 4-ethylenedioxythiophene), PEDOT] were fabricated and their photovoltaic performance were investigated. In CdS QDSSC, the organic C₇H₅N₄S^-/C₁₄H₁₀N₈S₂electrolyte shows better performance than the polysulfide electrolyte, and the PEDOT counter electrode exhibits higher efficiency than that of the Pt counter electrode and the CoS counter electrode. An efficiency of 1.53% was achieved in this QDSSC. The influences of the morphology and the deposition charge of the PEDOT counter electrodes on the cell performance were also studied. Furthermore, it was found that the C₇H₅N₄S^-/C₁₄H₁₀N₈S₂redox couple outperformed the C₂H₃N₄S^-/C₄H₆N₈S₂redox couple due to reduced electron recombination.