Boosting carbon quantum dots/fullerene electron transfer via surface group engineering
Alberto Privitera1, Marcello Righetto1, Dario Mosconi1
1Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy. lorenzo.franco@unipd.it.
Physical Chemistry Chemical Physics : PCCP
|November 9, 2016
Summary
Nitrogen-doped carbon quantum dots (CQDs) were functionalized to improve their electron-donor properties and solubility for photovoltaic applications. These enhanced CQDs demonstrate efficient electron transfer with PCBM, paving the way for all-carbon solar cells.
Area of Science:
- Materials Science
- Photovoltaics
- Nanotechnology
Background:
- Developing cost-effective, environmentally friendly materials for third-generation photovoltaics remains a challenge.
- Carbon quantum dots (CQDs) show promise but suffer from poor processability and electron-donor capabilities.
- Functionalization is key to overcoming these limitations for photovoltaic applications.
Purpose of the Study:
- To synthesize and characterize N-doped CQDs functionalized with thiophene groups to enhance their electron-donor properties and solubility.
- To investigate the photoinduced interactions between functionalized CQDs and PCBM for photovoltaic applications.
- To assess the potential of these materials for developing "all-carbon" photovoltaic devices.
Main Methods:
- Synthesis and photophysical characterization of N-doped CQDs functionalized with thiophene-containing groups.
- Investigation of CQD-PCBM interactions in solution and solid blends using cyclic voltammetry, photoluminescence spectroscopy, and electron paramagnetic resonance (EPR).
- Time-resolved EPR spectroscopy to analyze charge transport efficiency.
Main Results:
- Functionalized CQDs exhibited enhanced solubility in nonpolar solvents and a significant shift in oxidation potential, indicating improved electron-donor capabilities.
- Efficient fluorescence quenching was observed in solution, with total quenching in solid blends, confirming electron transfer between CQDs and PCBM.
- EPR spectroscopy confirmed photoinduced electron transfer via the formation of a PCBM radical anion, with time-resolved EPR revealing differences in charge transport.
Conclusions:
- Functionalized N-doped CQDs possess enhanced processability and electron-donor properties suitable for photovoltaic applications.
- The demonstrated efficient charge generation and separation between CQDs and PCBM are promising for future "all-carbon" solar cells.
- This work provides a pathway towards developing novel, sustainable photovoltaic technologies.
