How titanium dioxide helps create transparent solar cells

The climate transition requires solutions for a carbon-free future and new innovative methods to produce green energy. A new breakthrough opens doors to personalised sustainable energy.

A new study has unlocked the path towards affordability and production of the first invisible solar cells by coupling unique properties of Titanium Dioxide (TiO2) and of Nickel Oxide (NiO). Thanks to its “invisible” or transparent nature, the solar cells can be integrated into windows, vehicles, cell phone screens, and other everyday products.

Professor Joondong Kim and colleagues from Incheon National University in South Korea published their findings on the Journal of Power Sources in January 2021. The team highlighted that TiO2 is an ideal semiconductor in the solar cells as it absorbs invisible ultraviolet light while still letting the visible light pass through them. Additionally, it is also environmentally friendly making it easier to use.

The study could bring a wave of innovation in the realm of photovoltaic cells (PVCs). Current solar panels tend to be opaque, meaning that they are constrained to being lined up on roofs and in remote solar farms. These constraints brought Professor Joondong Kim and his colleagues to find new materials. Their findings were encouraging; with a power conversion efficiency of 2.1%, the cell’s performance was quite satisfactory, given that it targets only a small part of the light spectrum. The cell was also highly responsive and worked in low light conditions. Furthermore, more than 57% of visible light was transmitted through the cell’s layers, giving the cell this transparent aspect.

The researchers also managed to demonstrate how the solar cells could power a small motor. Prof. Kim highlighted that: “While this innovative solar cell is still very much in its infancy, our results strongly suggest that further improvement is possible for transparent photovoltaics by optimizing the cell’s optical and electrical properties,” The research team hopes to improve the efficiency of the solar cells in the near future.

The potential of the technology in the future of clean energy is clear. It opens the door to personalised green energy across sectors by its integration in a long range of everyday materials.