Carbon Nanotubes
Is “hybrid” the buzz word of the first decade of the 21st century? I am beginning to think so after learning about the prospect of hybrid solar cells. What can be “hybrid” about solar cells – either they use sunlight or they do not, right? That’s what I first thought until I saw the light!
Hybrid solar cells actually will have greater efficiency than their non-hybrid counterparts. This is because of a unique combination of solar cell components: semiconductor nanoparticles and carbon nanotubes.
Now, those are some pretty big words, if you are not into nanotechnology. First, let’s watch this video in which carbon nanotubes are explained.
Now, I’ll break down the basic information of the two primary components of hybrid solar cells.
Semiconductor nanocrystals
Semiconductor nanocrystals have a broad absorption spectrum, meaning that they can get energy from light of all colors of the rainbow (ultraviolet to infrared). Obviously, this translates to greater efficiency as more light wavelengths are viable sources of energy. The semiconductor nanocrystals can be covered by ultra thin layers of other semiconductor materials which improve stability. For example, solar ink. As described on Wikipedia:
A layer of crystalline nanoparticles is used in a new type of solar panel named SolarPly made by Nanosolar. It is cheaper than other solar panels, more flexible, and claims 12% efficiency. (Conventionally inexpensive organic solar panels convert 9% of the sun’s energy into electricity.) Crystal tetrapods 40 nanometers wide convert photons into electricity, but only have 3% efficiency.
The following video shows that the thin film solar cells are less expensive than silicon-based cells and also more versatile:
The drawback of semiconductor-based solar cells is that they are quite fragile and any type of material that is added for strength reduces the conduction of electricity. Carbon nanotubes appear to be the answer!
Carbon nanotubes are extremely durable and also conductive. That means that they can cover the fragile nanocrystalline conductor solar cells without reducing electrical conductivity. Hybrid solar cells, which are still under development by researchers at Instituto Madrileno de Estudios Avanzados en Nanosciencia (IMDEA Nanoscience), , would combine both properties (efficiency and durability) into the greatest solar cells and photovoltaic devices under the sun.
The scientific community is in agreement that the hybrid solar cell technology appears to be quite viable and will also be very affordable. My humble opinion is that we will see some pretty significant advancements in this field in the next year or too. And I can’t wait.
