A Wiki for Perovskite Solar Cell Research
An international team of experts has collected data on metal halide perovskite solar cells from more than 15,000 publications and developed a database with visualisation options and analysis tools. The database is open source and provides an overview of the rapidly growing knowledge as well as the open questions in this exciting class of materials. The study was initiated by HZB scientist Dr. Eva Unger and implemented and coordinated by her postdoc Jesper Jacobsson.
Halide perovskites have huge potential for solar cells and other optoelectronic applications. Solar cells based on metal-organic perovskites achieve efficiencies of more than 25 percent, they can be produced cheaply and with minimal energy consumption, but still require improvements in terms of stability and reliability. In recent years, research on this class of materials has boomed, producing a flood of results that is almost impossible to keep track of by traditional means. Under the keyword "perovskite solar", more than 19,000 publications had already been entered in the Web of Science (spring 2021).
FAIR data
Now 95 experts from more than 30 international research institutions have designed a database to systematically record findings on perovskite semiconductors. The data are prepared according to the FAIR principles, i.e. they are findable, accessible, interoperable and reusable. By reading the existing literature, the experts have collected more than 42,000 individual data sets, in which the data can be filtered and displayed according to various criteria such as material compositions or component type. Researchers from several teams at HZB were involved in this Herculean task.
New insights by AI
"Data has always been the basis of empirical science, but when data is collected in sufficiently large quantities and in a coherent way, it can be searched with modern algorithms and artificial intelligence and can provide completely new insights," says Jesper Jacobsson, coordinator of this project.
Interactive tools, easy uploads
The database provides analysis tools and graphical data visualizations that enable easy and interactive exploration, and also offers the option to easily upload new data from new peer-reviewed publications. "It's a wiki for perovskite solar cell research," says Eva Unger, counting on the participation of the research community: "In the future, this type of research data platform will offer us the opportunity to make our research data public according to FAIR principles in addition to established publication formats."
Not only science, but also industry will benefit: The database provides an overview of the current state of knowledge, while also uncovering gaps in knowledge from which new productive research questions can arise.
- Battery research: visualisation of aging processes operandoLithium button cells with electrodes made of nickel-manganese-cobalt oxides (NMC) are very powerful. Unfortunately, their capacity decreases over time. Now, for the first time, a team has used a non-destructive method to observe how the elemental composition of the individual layers in a button cell changes during charging cycles. The study, now published in the journal Small, involved teams from the Physikalisch-Technische Bundesanstalt (PTB), the University of Münster, researchers from the SyncLab research group at HZB and the BLiX laboratory at the Technical University of Berlin. Measurements were carried out in the BLiX laboratory and at the BESSY II synchrotron radiation source.
- New instrument at BESSY II: The OÆSE endstation in EMILA new instrument is now available at BESSY II for investigating catalyst materials, battery electrodes and other energy devices under operating conditions: the Operando Absorption and Emission Spectroscopy on EMIL (OÆSE) endstation in the Energy Materials In-situ Laboratory Berlin (EMIL). A team led by Raul Garcia-Diez and Marcus Bär showcases the instrument’s capabilities via a proof-of-concept study on electrodeposited copper.
- Green hydrogen: A cage structured material transforms into a performant catalystClathrates are characterised by a complex cage structure that provides space for guest ions too. Now, for the first time, a team has investigated the suitability of clathrates as catalysts for electrolytic hydrogen production with impressive results: the clathrate sample was even more efficient and robust than currently used nickel-based catalysts. They also found a reason for this enhanced performance. Measurements at BESSY II showed that the clathrates undergo structural changes during the catalytic reaction: the three-dimensional cage structure decays into ultra-thin nanosheets that allow maximum contact with active catalytic centres. The study has been published in the journal ‘Angewandte Chemie’.