A thin film developed by the ICMS coats nanogenerators that produce electricity through the impact of raindrops, whilst also improving the durability of photovoltaic cells
The research opens up new avenues for developing self-powered electronic systems designed for outdoor use
A team from the Seville Institute of Materials Science (ICMS), a joint centre of the Spanish National Research Council (CSIC) and the University of Seville (US), has developed a new hybrid device that can simultaneously capture energy from both the sun and rain. It consists of a thin film created and patented by the research team that not only protects and improves the durability of perovskite solar cells, even in adverse weather conditions, but also enables nanogenerators to produce over 100 volts from the impact of a single drop of water—enough to power small portable devices.
Halide perovskite solar cells are photovoltaic devices composed of synthetic materials with a crystalline structure and excellent sunlight absorption properties. Although silicon technology is the most widely used, perovskite technology has great potential to revolutionise photovoltaic energy due to its high efficiency and low cost. However, their degradation or instability under environmental conditions is one of their main drawbacks. Faced with this challenge, the ICMS research team has used plasma technology to create and deposit a protective layer of around 100 nanometres onto the solar cells. On the one hand, this system acts as an encapsulant that chemically protects the perovskite cells and optically enhances their ability to absorb light; and, on the other hand, it possesses a triboelectric surface (which generates an electric charge through friction or contact) that converts the kinetic energy of raindrops into an electric current.
The results demonstrate the new material’s ability to generate up to 110 volts from the impact of a single raindrop, sufficient to power a small portable device. In addition to being scalable and produced using sustainable techniques, the coatings have demonstrated remarkable stability in extreme environments such as immersion in water; they can continuously power simple electronic devices, such as LED circuits; and they enable solar panels to withstand environmental conditions associated with humidity-temperature stress cycles.
“Our work proposes an advanced solution that combines perovskite solar cell photovoltaic technology with triboelectric nanogenerators in a thin-film configuration, thereby demonstrating the viability of implementing both energy harvesting systems,” explains Carmen López, a researcher at the ICMS.
Reducing reliance on batteries
In response to the limitations of conventional batteries and the loss of efficiency in solar panels on cloudy days, this technological advance aims to propose an innovative solution based on the sun-rain symbiosis. Its purpose is to provide energy autonomy to portable and wireless electronic devices, enabling their continuous operation in both sunny and rainy conditions.
The authors highlight that the device developed represents a significant innovation for the entire Internet of Things (IoT) industry, including environmental sensors (humidity, rain, pollution), structural sensors (bridges, buildings), weather stations and precision agriculture.
“Its implementation in so-called smart cities is viable, for example in signage, autonomous auxiliary lighting or monitoring, as it withstands adverse weather conditions and the presence of rain, humidity and thermal cycles. It would also be applicable to distributed energy structures in remote, inaccessible or isolated areas, such as marine stations,” notes ICMS researcher Fernando Núñez.
The work offers a novel approach that opens up new avenues for developing autonomous and robust electronic systems intended for outdoor use. “Our research highlights the potential of coatings deposited using plasma techniques as a multifunctional solution that protects sensitive energy devices and enables the development of systems capable of harvesting energy from various environmental sources, such as hybrid solar-rain panels, known as ‘rain panels’,” the researchers conclude.
These results have been achieved thanks to the 3DScavenegrs project, funded by the European Research Council (ERC Starting Grant), and the Drop Ener project, co-funded by Next Generation funds, which have enabled progress in the development of triboelectric raindrop nanogenerators protected by the Energy Harvesting Device patent.
Fernando Núñez-Gálvez, Xabier García-Casas, Lidia Contreras-Bernal, Alejandro Descalzo, José Manuel Obrero-Pérez, Javier Castillo-Seoane, Antonio Ginés, Gildas Leger, Juan Carlos Sánchez-Lopez, Juan Pedro Espinós, Ángel Barranco, Ana Borrás, Juan Ramón Sánchez-Valencia, Carmen López-Santos. Water-resistant hybrid perovskite solar cell – drop triboelectric energy harvester. Nano Energy. DOI: doi.org/10.1016/j.nanoen.2025.111678