TiO2/PbS(CdS) quantum dots (QDs) bulk heterojunction has been fabricated by successive ionic layer adsorption and reaction method via alternate deposition of PbS and CdS QDs. In comparison with TiO2/PbS heterojunction, the incident photon to current conversion efficiency was increased almost 50% in the visible region. Meantime, the short-circuit current and open-circuit voltage were enhanced 200% and 35% respectively. The influence mechanism of CdS is related to reduction of trap state density at TiO2/PbS interface and PbS QDs surface by the discussion of the dark current density-voltage curves, the transient photocurrent response curves and the electrochemical impedance spectra spectroscopy (EIS). (C) 2016 Published by Elsevier Ltd.
机构:
Chongqing Univ, Sch Mat Sci & Engn, State Key Lab Mech Transmiss, Chongqing 400044, Peoples R ChinaChongqing Univ, Sch Mat Sci & Engn, State Key Lab Mech Transmiss, Chongqing 400044, Peoples R China