Researchers from Qatar, Switzerland and Italy have created a new waterproof material to coat solar panels, designed to increase the stability and efficiency of solar cells and tackle the problem of water-induced degradation.
A low-dimensional composite perovskite material, it has a thin surface layer that repels water and protects against moisture-induced degradation, a problem with perovskites, which are currently under investigation for more widespread use in solar cells.
The material was created by allowing the self-assembly of two-dimensional perovskite on top of a 3D perovskite in an inert atmosphere. Researchers found the perovskite did not decompose when left for three days in humid air as the top layer of 2D perovskite blocked water penetration into the 3D perovskite below. If left unprotected, 3D perovskite usually degrades when left in high humidity.
Solar cells made with the new composite perovskite showed 20% efficiency in converting solar power into electricity and maintained efficacy for 200 hours, a heightened performance that was attributed to the top water-resistant layer.
Study co-author Mohammad Khaja Nazeeruddin said that the material could be employed in other devices, such as light-emitting diodes and photodetectors.
The next step for the team is to optimise the material and examine it for other applications.
Perovskite is a compound most commonly made up of a hybrid of organic-inorganic lead or a tin halide-based material and can be used as the light-harvesting active layer in solar cells. Able to be grown in the lab, synthetic perovskites are relatively cheap and can be used in a thin-film format.
High efficacy and ease of manufacture have made it a favoured material for research in the solar industry, with industry members predicting the introduction of perovskite technology could drive the price of solar down even further beyond conventional silicon solar cells. However, low device lifetime due to material degradation caused by water exposure has proven a hindrance to its commercialisation.
Other firms working to tackle the issue of water-induced degradation include the EU consortium Solliance, which announced last November that its thin film perovskite solar cell had reached photovoltaic performance of 13.5%.