Surfactant-free water-processable photoconductive all-carbon composite

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Heterojunctions of graphitic nanostructures are promising for light-to-electrical energy conversion.
• Current fabrication methods often require covalent linking or functionalization, which can degrade material properties.

Purpose of the Study:

• To develop a facile method for creating all-carbon nanocomposites for optoelectronic applications.
• To overcome the solubility limitations of graphitic nanostructures.

Main Methods:

• Coassembly of fullerenes, single-walled carbon nanotubes, and graphene oxide in water.
• Thermal reduction of graphene oxide to form a stable hybrid.
• Fabrication of thin films and photovoltaic devices.

Main Results:

• A stable, water-dispersible colloidal hybrid of fullerene-nanotube-graphene was achieved.
• The resulting all-carbon hybrid exhibited a photoconductive on-off ratio of nearly 6 orders of magnitude.
• Photovoltaic devices demonstrated unprecedented performance for all-carbon materials, with an open-circuit voltage of 0.59 V and 21% power conversion efficiency.

Conclusions:

• Surfactant-free, water-processed all-carbon thin films can be readily fabricated.
• These materials show significant potential for applications in organic optoelectronic devices.