By improving upon their earlier design on photoactive crystal tungsten diselenide, a team at Vienna University of Technology has come up with a thin, flat solar cell which could be used in glass panes to let in light, and also generate electricity.
The team had produced an ultra-thin layer of the photoactive crystal tungsten diselenide. A semiconductor comprising a layer of tungsten sandwiched between two layers of selenium atoms, this could turn light into electricity and vice versa.
When light shines on a photoactive material, single electrons are removed from their original position. A positively charged 'hole' remains, where the electron used to be. The movement of the electron and hole produces electricity.
But to prevent the electrons and holes (positive charge) from recombining, it requires many tiny electrodes placed between the layers to draw away the charge.
Instead, when combined with molybdenium disulphide, the holes move inside the tungsten diselenide layer, and the electrons migrate into the molybednium disulphide.