|A prototype of a new type of photovoltaic (PV) cell that generates electricity from visible, infrared and ultraviolet light has been demonstrated by a group of Japanese scientists. It could lead to the development of a highly-efficient PV cell in the future, without needing multijunction cells.|
The research was led by Associate Professor Saki Sonoda of the Kyoto Institute of Technology. The prototype cell has a high open voltage (Voc) at around two volts, but a low energy conversion efficiency. Sonada and the team hope the conversion rates can be improved.
Photovoltaic materials convert light to electricity at the atomic level by absorbing photons of light and releasing electrons that can be captured to produce an electric current. Most PV cells are multijunction devices, with single junction cells stacked in descending order of band gap. The cell at the top captures high-energy photons, while those at the bottom with lower band gaps capture the lower energy photons. The new cell is able to capture photons with a wide range of energies in a single junction cell.