Researchers in Cornell University have come up with a novel idea for making solar cells more efficient. Rather than using traditional silicon, researchers used a carbon nanotube and created the basic elements of a solar cell that has been proven to be much more efficient in the conversion of light to electrical energy, as compared to the technology that is used at present in calculators as well as on rooftops. Read more about Nanotechnology and Photovoltaics Trends & Market Potential

Research at Cornell constructed, tested and also measured a very basic solar photovoltaic cell called a photodiode. The photodiode is constructed from an individual carbon nanotube. The research was first reported in the September issue of the journal science, in which the researchers detailed how the simple solar cell transforms light to electrical energy in a highly efficient procedure that doubles the quantity of electrical current that flows through. The team of researchers was led by Paul McEuen, the Goldwin Smith Professor of Physics, and Jiwoong Park, assistant professor of chemistry and chemical biology. According to the researchers, this method of constructing more efficient solar cells is going to be crucial for the improvement of the next generation high efficiency solar cells.

According to students from McEuen’s class, the team worked towards creating not just a new material, but also putting it into application by creating a new and more effective solar cell device.

To create their solar photovoltaic cell, the researchers from Cornell utilized a single walled carbon nanotube. A single walled carbon is basically a rolled-up sheet of graphene. The nanotube was near about the size of a DNA molecule and it was wired between two electrical contacts and close to two electrical gates, one negatively and one positively charged. The work of the researchers was inspired by some part through previous research done by scientists where they created a diode. A diode is basically a simple transistor that allows current to flow in only one direction, using a single-walled nanotube. The Cornell team of researchers followed an almost similar pattern but they followed it up by shining light on to it.

By shining different colored lasers onto various areas of the nanotube, they discovered that the greater levels of photon energy had a doubling impact on the amount of electrical current being produced.

Apart from this, on further researching the same, researchers found that the narrow and cylindrical structure of the carbon nanotube caused the electrons to be neatly squeezed through one by one. The electrons moving through the nanotube became excited and created new electrons that continued to flow. They discovered that the nanotube may almost be an ideal photovoltaic cell because it allowed electrons to produce more electrons by using the leftover energy from the light.

This is dissimilar to the present-day solar cells in that in today’s solar cells, the extra bit of energy is lost in the form of heat and therefore, the solar cells require a lot of constant externally provided cooling.

The main problem at the moment with this new and advanced device is that it is going to be a problem to bring down the cost of the technology. Also, the reliability of the technology also has to be allowed.