Efficient plasmonic dye-sensitized solar cells with fluorescent Au-encapsulated C-dots

Area of Science:

• Materials Science
• Nanotechnology
• Renewable Energy

Background:

• Dye-sensitized solar cells (DSSCs) are a promising photovoltaic technology.
• Improving the energy conversion efficiency of DSSCs is crucial for their commercial viability.
• ZnO nanorods offer a suitable scaffold for DSSC photoanodes.

Purpose of the Study:

• To enhance the efficiency of ZnO-nanorod-based DSSCs.
• To investigate the effect of Au-encapsulated carbon dots (Au@C-dots) on DSSC performance.
• To explore the mechanisms of plasmonic resonance and Förster Resonance Energy Transfer (FRET) in DSSCs.

Main Methods:

• Fabrication of DSSCs with ZnO/N719/Au@C-dots photoanodes.
• Characterization of Au@C-dots for localized surface plasmon resonance (LSPR) in the 500-550 nm range.
• Analysis of charge transfer using fluorescence and lifetime measurements.
• Quantification of FRET from ZnO nanorods to N719 dye.

Main Results:

• Au@C-dots enhanced energy harvesting due to LSPR and charge separation.
• Charge transfer from N719 dye to Au@C-dots was confirmed.
• FRET from ZnO nanorods to N719 dye occurred with a rate of 4.4×10^8 s^-1 and a Forster radius of 1.89 nm.
• The plasmonic and FRET-enabled DSSC achieved an overall power conversion efficiency of 4.1%, a 29% improvement over traditional cells.

Conclusions:

• Au@C-dots are effective in improving DSSC efficiency.
• The combination of LSPR and FRET mechanisms significantly enhances energy conversion.
• This strategy offers a viable pathway for developing more efficient solar cells.