A Facile Protocol for Designing the CdS/PbS Multi Layered Quantum Dots with Enhanced Photoelectrochemical Performance

Photocatalysts play a vital role in solar cell performances; solar cells are 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. The multi-layered quantum dots containing CdS and different layers of n-type of PbS (2, 4, 6 cycles) have been used to improve photoanodes sensitivity through the successive ionic layer adsorption and reaction (SILAR) with a coat of TiO2 nanoparticles on the ITO substrates. CuS was used as a counter electrode for all cells. The film s behavior was examined in the darkness and under simulated sunlight (200 mW cm^-2) with electrochemical techniques including chronoamperometry, chronopotentiometry, electrochemical impedance spectroscopy and linear sweep voltammetry. The morphology of the prepared films was investigated by scanning electron microscopy and energy dispersive X-Ray spectroscopy. 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 potential of 1.5 V, in which the constant potential current of 1.5 V led to the cm^2 difference in chronoamperometry by 18 μA cm^-2.