Efficient CdPbS quantum dots-sensitized TiO2 photoelectrodes for solar cell applications

Area of Science:

• Materials Science
• Nanotechnology
• Photovoltaics

Background:

• Quantum dots (QDs) offer tunable optical and electronic properties for photovoltaic applications.
• Titanium dioxide (TiO2) is a widely used semiconductor in solar cell technologies.
• Improving the efficiency of quantum dot-sensitized solar cells (QDSSCs) is crucial for their commercial viability.

Purpose of the Study:

• To synthesize CdPbS quantum dots and integrate them into a TiO2 photoelectrode.
• To investigate the photovoltaic performance of QDSSCs utilizing CdPbS QDs.
• To compare the performance of CdPbS QDSSCs with other QDSSC configurations.

Main Methods:

• Chemical bath codeposition technique was employed to prepare the CdPbS QDs-sensitized TiO2 photoelectrode.
• Dipping a TiO2 film into specific cadmium nitrate-lead nitrate and sodium sulfide solutions.
• Characterization of CdPbS QDs size (4-6 nm) and homogeneous distribution within the TiO2 film.

Main Results:

• The CdPbS QDs-sensitized TiO2 photoelectrode exhibited enhanced absorption spectra.
• The assembled QDSSC achieved a power conversion efficiency (η) of 1.88% and a short-circuit current (Jsc) of 15.28 mA/cm².
• Performance significantly surpassed single PbS or CdS QDSSCs and showed a 49.2% efficiency increase over coupled PbS/CdS QDSSCs.

Conclusions:

• CdPbS quantum dots are effective sensitizers for TiO2 photoelectrodes in QDSSCs.
• The developed QDSSC demonstrates superior photovoltaic performance, covering visible and near-infrared regions.
• This advancement holds promise for more efficient and broader-spectrum solar energy harvesting.