The use of narrow band gap semiconductors such as PbS may expand the light absorption range to the near-infrared region in quantum-dot-sensitized solar cells (QDSCs), increasing the generated photocurrent. However, the application of PbS as a sensitizer in QDSCs causes some problems of stability and high recombination. Here, we show that the direct growth of a CdS coating layer on previously deposited PbS by the simple method of successive ionic layer adsorption and reaction (SILAR) minimizes these problems. A remarkable short-circuit current density for PbS/CdS QDSCs is demonstrated, !11 mA/ cm2, compared to that of PbS QDSCs, with photocurrents lower than 4 mA/cm2, using polysulfide electrolyte in both cells. The cell efficiency reached a promising 2.21% under 1 sun of simulated irradiation (AM1.5G, 100 mW/cm2). Enhancement of the solar cell performance beyond the arithmetic addition of the efficiencies of the single constituents (PbS and CdS) is demonstrated for the nanocomposite PbS/CdS configuration. PbS dramatically increases the obtained photocurrents, and the CdS coating stabilizes the solar cell behavior.
|Data di pubblicazione:||2011|
|Titolo:||Panchromatic Sensitized Solar Cells Based on Metal Sulfide Quantum Dots Grown Directly on Nanostructured TiO2 Electrodes|
|Rivista:||THE JOURNAL OF PHYSICAL CHEMISTRY LETTERS|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1021/jz2000112|
|Appare nelle tipologie:||2.1 Articolo su rivista |