Carbon nanotubes improve solar cell technology

Researchers in the United Kingdom have developed an ultra-hybrid power from multi-walled carbon nanotubes and In-Sn oxides that can be used for solar cell applications.

Carbon nanotubes that are grown directly from the InSn coated glass substrate act as transparent electrodes often used in optoelectronic devices such as solar cells, LED . Carbon nanotube electrodes for allowing transmission over longer wavelengths and making them ideal for harnessing solar energy.

Multi-walled carbon nanotubes (Photo: chem.tue.nl)

Organic solar cells are cheaper and easier to manufacture than inorganic materials, but their performance and lifetime are a major problem due to the mobility of carriers (especially holes). drum) is low, limiting the current transfer in the device. One way to improve this is to reduce the active layer thickness, but this also leads to a reduction in photovoltaic cell absorption.

Another approach of the group Ravi Silva and colleagues at the Nano Electronics Center, the Institute of High Technology, University of Surrey (United Kingdom) is to use electrodes penetrating deep in the inorganic and impacted layers. Make electrical carriers so that they become free to move in device .

Silva's group has shown that it is possible to create multi-walled carbon nanotubes that grow directly from InSn oxide-coated glass substrates by chemical vapor deposition (Chemical Vapor Deposition - CVD). Multi-walled carbon nanotubes have very good thermal and electrical conductivity and therefore can act as a buffer electrode layer. Scientists have demonstrated that carbon nanotubes will penetrate electrodes under a large surface area and effectively help increase the mobility of positive charges from inorganic active layers. .

"Mainly, these electrodes have a high transmittance with long wavelengths in particular making them more suitable for the sun's spectrum ," said Silva. (Speaking on NanotechWeb.org).

In addition, the results show that carbon nanotubes grow on the InSn oxide more slowly than many other materials, and moreover, direct contact with the substrate, while significantly improving the mechanical properties of the device .

The team tested photovoltaic cells using " artificial sunlight " with a capacity of 100 mW / cm2. The results show that the quality is improved by more than 30% with an overall efficiency of around 1%. The results of this study were published in Appl. Phys. Lett. 90 (2007) 023105.

(Photo: Vietnamese Physics)

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