Efficient PbS/CdS co-sensitized solar cells based on TiO2 nanorod arrays
1 School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, People’s Republic of China
2 School of Information Science and Engineering, Shandong University, Jinan, 250100, People’s Republic of China
3 Department of Mechanical and Materials Engineering, Portland State University, P.O. Box 751, Portland, OR, 97207-0751, USA
4 Department of Physics, Portland State University, P.O. Box 751, Portland, OR, 97207-0751, USA
Nanoscale Research Letters 2013, 8:67 doi:10.1186/1556-276X-8-67Published: 11 February 2013
Narrow bandgap PbS nanoparticles, which may expand the light absorption range to the near-infrared region, were deposited on TiO2 nanorod arrays by successive ionic layer adsorption and reaction method to make a photoanode for quantum dot-sensitized solar cells (QDSCs). The thicknesses of PbS nanoparticles were optimized to enhance the photovoltaic performance of PbS QDSCs. A uniform CdS layer was directly coated on previously grown PbS-TiO2 photoanode to protect the PbS from the chemical attack of polysulfide electrolytes. A remarkable short-circuit photocurrent density (approximately 10.4 mA/cm2) for PbS/CdS co-sensitized solar cell was recorded while the photocurrent density of only PbS-sensitized solar cells was lower than 3 mA/cm2. The power conversion efficiency of the PbS/CdS co-sensitized solar cell reached 1.3%, which was beyond the arithmetic addition of the efficiencies of single constituents (PbS and CdS). These results indicate that the synergistic combination of PbS with CdS may provide a stable and effective sensitizer for practical solar cell applications.