The experts sought inspiration from the electronics industry as the field is known for its miniaturization techniques.
But, the challenge was to deposit light absorbers onto lightweight substrates and protect them against water infiltration. To overcome these, the team used thin-film metal oxides and, which can be coated onto flexible plastic and metal foils. The devices were covered with micrometer-thin, water-repellent carbon-based layers that prevented moisture degradation.
"This study demonstrates that artificial leaves are compatible with modern fabrication techniques, representing an early step towards the automation and up-scaling of solar fuel production," said Andrei. "These leaves combine the advantages of most solar fuel technologies, as they achieve the low weight of powder suspensions and the high performance of wired systems.
"Many renewable energy technologies, including solar fuel technologies, can take up large amounts of space on land, so moving production to open water would mean that clean energy and land use aren’t competing with one another," said Reisner. "In theory, you could roll up these devices and put them almost anywhere, in almost any country, which would also help with energy security.