A quantum dot solar cell is mainly the type of cell design which makes use of quantum dots as the key absorbing photovoltaic material. These solar cells are designed so that they can increase the maximum thermodynamic conversion efficiency which can be attained by as much as 66%.
When quantum dots are used, the design aims at replacing the different bulk materials like copper, silicon, cadmium telluride and more. They also come with band gaps which are also tunable. By changing their size, they are able to spread over a varied range of energy levels. On the contrary, when it comes to bulk materials, the band gap gets fixed due to the materials chosen. It is this flexibility offered by quantum dots which makes them really attractive and thereby finds its use in multi-junction solar cells.
What are quantum dots mainly?
They are essentially semi conducting particles whose size has been reduced even less than that of Exciton Bohr radius. As per the dynamics of quantum mechanics, the energy inside the electron tends to become finite unlike those present in the atoms. This is another reason as to why quantum dots are also referred to as artificial atoms. Whenever the sizes of these dots are altered, it ends up shaping and altering the energy levels and therefore the band gap gets defined accordingly.
As the band gap can be tuned, these dots become best suitable for solar cells. They are not yet available on the mass scale for commercial use. But a lot of companies and commercial service providers have started using it for photovoltaic products. There is no doubt that these are likely to be the next big thing as far as the solar industry is concerned.
There are a few heavy metal quantum dots that need to be thoroughly encapsulated in polymer shell that is stable. This needs to be done to avoid any kind of exposure as they can be cytotoxic.
Those that are not toxic have been put to several tests and use and they seem to be a great and lucrative option for tapping the most of solar power. When quantum dots are tapped to their full potential, they may end up opening an altogether new avenue for the generation of solar power and putting it several constructive uses.
As more and more awareness is being generated regarding how semi conductor nanostructures can be used for generating immense amount of energy, there has been a massive development in the field of solar cells as well.