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Subpicosecond Hot Hole Transfer in a Graphene Quantum Dot Composite with High Efficiency
Krishna Mishra1, Debopam Acharjee1, Ayendrila Das1
1School of Chemical Sciences, National Institute of Science Education and Research, Homi Bhabha National Institute (HBNI), Khurda 752050, Odisha, India.
The Journal of Physical Chemistry Letters
|January 12, 2022
Summary
Colloidal graphene quantum dots (GQDs) exhibit significantly slower hot carrier cooling times than bulk materials. This property enables efficient harvesting of high-energy species, enhancing optoelectronic device performance.
Area of Science:
- Materials Science
- Nanotechnology
- Optoelectronics
Background:
- Hot carrier extraction is crucial for improving optoelectronic device efficiency by minimizing energy loss.
- Colloidal graphene quantum dots (GQDs) offer potential for advanced optoelectronic applications.
Purpose of the Study:
- To investigate the carrier cooling dynamics of colloidal graphene quantum dots (GQDs).
- To explore the feasibility of utilizing GQDs for efficient hot carrier extraction in optoelectronic devices.
Main Methods:
- Femtosecond upconversion spectroscopy was employed to measure carrier cooling times.
- A GQD-molecular system composite was designed to facilitate hot hole transfer.
Main Results:
- Colloidal GQDs exhibit carrier cooling times on the order of picoseconds, which is significantly slower than their bulk counterparts.
- A subpicosecond hot hole transfer time with high efficiency was achieved in a GQD-molecular system.
- The slower cooling rate of GQDs is advantageous for harvesting high-energy carriers.
Conclusions:
- The slow carrier cooling in colloidal GQDs is a key property for efficient energy harvesting.
- Graphene quantum dots show promise for dramatically enhancing the efficiency of GQD-based optoelectronic devices.
