Document Type : Regular Article
Department of Chemistry, K.N. Toosi University of Technology, P. O. Box: 15875-4416, Tehran, Iran
Since photocatalysts play a vital role in solar cell performance, and solar cells are also an effective source of green energy. In this paper,a facile and affordable protocol for designing an effective photoanode based on the quantum dot was introduced. multi-layered quantum dots containing CdS and different layers of n-type of PbS (2, 4, 6cycles)has been used to improve photoanodes sensitivity through the successive ionic layer adsorption and reaction(SILAR)with a coat of TiO2 nanoparticles on ITO substrates.CuS was used as a counter electrode for all cells. The film's behavior was examined in the dark and under simulated sunlight (200 mW cm-2) with electrochemical techniques (chronoamperometry(CA), chronopotentiometry(CE), electrochemical impedance spectroscopy (EIS), linear sweep voltammetry(LSV)). The morphology of prepared films was investigated by scanning electron microscopy(SEM) and energy dispersive X-Ray spectroscopy (EDS). The results for the TiO2/4CdS/4PbS film revealed that developing multi-layered cells could improve the quantum dot sensitivity and the performance of the cell in case of reaching the optical layer.The TiO2/4CdS/4PbS electrode improved the sensitivity of the cell remarkably and the maximum difference between light and darkness was observed in the 1.5 V potential, in which the constant 1.5 V potential current lead to the 18 µA/cm2 difference in chronoamperometry.