PbS quantum dot sensitized anatase TiO2 nanocorals for quantum dot-sensitized solar cell applications

Abstract

Lead sulphide (PbS) quantum dot (QD) sensitized anatase TiO₂ nanocorals (TNC) were synthesized by SILAR and hydrothermal techniques. The TNC, PbS and PbS–TNC samples were characterized by optical absorption, XRD, FT-IR, FESEM and XPS. The results show that PbS QDs are coated on the TNCs, the optical absorption is found to be enhanced and the band edge is shifted to ∼693 nm as compared with plain TNCs at 340 nm. The PbS–TNC sample exhibits an improved photoelectrochemical performance with a maximum short circuit current (J_sc) of 3.84 mA cm⁻². The photocurrent density was found to be enhanced 2 fold, as compared with those of the bare PbS photoelectrode. The total power conversion efficiency of the PbS–TNC electrodes is 1.23%.