What if photovoltaic panels were transparent and functioned like a window?
Feb 23 2021

A team of Korean researchers has published a study on transparent photovoltaic cells that opens the door to using these plates as a source of power generation in windows, screens of mobile devices, vehicles…

Photovoltaic technology is set to be one of the main sources of energy generation in the coming years, especially in countries that, like Spain, have many hours of solar radiation. Solar panels are increasingly efficient and durable, however, the scientific community continues to research to design more cost-effective and reliable plates.

One of the drawbacks of conventional solar panels is that they are opaque, so they need to be installed in locations where they do not obstruct the vision of human beings. It is not feasible, for example, for a photovoltaic panel to be placed on a window, but until when?

Korean scientists have developed a study in which they assure that transparent solar cells may be a reality in the not too distant future. «This is a promising approach, because they do not require additional space for installation,» say the authors of this study.



How do they work?


The transparent photovoltaic cell (TPC) is a panel that lets light from the visible spectrum through while absorbing ultraviolet light to generate electrical power.

The researchers say that to make this type of transparent cells, two different chemical compounds must be used. First of all, titanium oxide (TiO2) is an ‘n’ type semiconductor that absorbs ultraviolet light. Secondly, on this layer another of nickel oxide (NiO) of type ‘p’ is deposited that allows the passage of more than 57% of the light of the visible range.

The efficiency of conversion of light into energy was 2.1%, a figure that could seem very poor when compared with the percentages of conventional cells, higher than 20%, although it is not negligible if one takes into account that the TPC only produce energy from a small part of the light spectrum.



TPC applications


The researchers defend that transparent photovoltaic cells can be an invisible energy source that could be applied on windows, on the screens of electronic devices (such as mobile phones, tablets …), in vehicles and buildings in general.

«Humans will be able to obtain electrical energy without losing vision range in the near future,» the study authors note.

«Although this innovative solar cell is still in its infancy, our results clearly suggest that transparent photovoltaics can be further improved by optimizing the optical and electrical properties of the cell,» said Professor Joondong Kim, one of the authors of the research.