Nanoscale Solar Cells Outperform Traditional Technology


Scientists have designed a novel type of nanoscale solar cell. Initial studies and computer modelling predict these cells will outperform traditional solar panels, reach power conversion levels by over 40 percent.

Solar power cells work through the conversion of sunlight into electricity using photovoltaics. Here solar energy is converted into direct current. A photovoltaic system uses several solar panels; with each panel composed of a number of solar cells. This combines to create a system for the supply usable solar power.

To investigate what is possible in terms of solar power, the researchers have examined the Shockley-Queisser limit for different materials. This equation describes the maximum solar energy conversion efficiency achievable for a particular material, allowing different materials to be compared as candidates for power generation.

Using this formula, most solar cells available today have an efficiency limit of 33 percent – which means they can convert into usable power about a third of the energy they collect. By examining what can happen at the nanoscale, researchers have come up with something far more efficient.

The scientists have produced a single-junction nanostructured solar cell. This type of solar cell appears to have an efficiency rating of 42 percent. While this may not sound like much, in terms of power utilization it is very significant.

Nanostructures can reduce the mismatch between absorption and emission angles. Photo source

This new technology could revolutionize the solar industry by allowing for significantly more power generation from a single device by simply making it much smaller. The biggest challenge with commercialization will be with nano-fabrication for mass production.

The research was carried out at the University of Maryland Department of Electrical and Computer Engineering, led by research scientist Jeremy Munday. The findings are published in the journal Scientific Reports. The paper is titled “The generalized Shockley-Queisser limit for nanostructured solar cells.”