Bifacial illuminated PbS quantum dot-sensitized solar cells with translucent CuS counter electrodes

This paper reports the optimization of the TiO 2 photoanode and the fabrication of bifacial illuminated PbS quantum dot-sensitized solar cells (QDSSCs) with translucent CuS counter electrodes. TiO 2 photoanode is prepared by introducing a compact TiO 2 layer between FTO substrate and TiO 2 film with titanium diisopropoxide bis(acetylacetonate) in 1-butanol and post-treatment with TiCl 4 aqueous solution; then, PbS quantum dots (QDs) are deposited on the surface of TiO 2 film by successive ionic layer adsorption and reaction method; also, by means of control of the TiO 2 surface charge, QD density of TiO 2 film is improved by adding triethanolamine into the cationic precursor solution. Using this optimized TiO 2 photoanode and a translucent CuS counter electrode, a bifacial illuminated PbS QDSSC is fabricated. The preparation conditions are optimized and the surface morphology and electrochemical properties of TiO 2 photoanodes are characterized. The bifacial illuminated PbS QDSSC achieves a power conversion efficiency of 2.16 %, which is increased by 48.97 % compared with the single illuminated QDSSC.