Researchers led by Joondong Kim, professor of electrical engineering at Incheon National University, Korea, recently showed the first visible solar cell. The team focused on the heterojunction, the thin films of material responsible for capturing light.
In today’s solar cells the semiconductor layers that are responsible for capturing light and translating it into an electric current make them obscure. So the team decided to explore the use of two other materials to make these films.
The first material, titanium dioxide (TiO2), a well-known semiconductor that is already widely used to make solar cells. It has excellent electrical properties and is environmentally friendly and non-toxic. Titanium dioxide absorbs UV light while emitting most of the visible light. The second material was nickel oxide (NiO), another semiconductor with optical transparency. Nickel is one of the most abundant elements on Earth, and it is easily oxidized at low industrial temperatures, making it a good candidate for the manufacture of eco-friendly solar cells.
The solar cell created by the team is prominent, which could allow future versions of it to be used in glass windows in homes and skyscrapers, as well as smaller applications such as watches and cell phones.Incheon National University
The team’s new solar cell consists of a glass substrate and a metal oxide electrolyte, with thin layers of semiconductors (TiO).2 first, then NiO) deposited on top of it. A final cover of silver nanowires will serve as the other electricity at the cell.
Tests showed that the cell had a power conversion efficiency of 2.1%, which the team says is good considering that the cell uses only a small portion of the light spectrum. The cell was also highly responsive and functioned in low light conditions. In addition, more than 57% of visible light is transmitted through the cell layer, making it visible. The researchers also showed that the cell can power a small motor.
“While this innovative solar cell is still largely in its infancy, our results strongly suggest that further improvements to visible photovoltaics are possible by improving the cell’s optical and electrical properties. , ”Kim suggests.