Perovskite solar cells: International consensus on ageing measurement protocols
© Catalan Institute of Nanoscience and Nanotechnology
Experts from 51 research institutions have now agreed on the procedures for measuring the stability of perovskite solar cells and assessing their quality. The consensus statement was published in Nature Energy and is considered a milestone for the further development of this new type of solar cell on its way to industrial application.
Commercially available solar modules undergo a series of characterisation procedures that analyse their properties and ensure quality. However, these methods cannot simply be transferred to halide perovskite solar cells. Halide perovskites are hybrid inorganic-organic materials for a new generation of solar cells, which have only been investigated for about eleven years. Perovskite solar cells achieve very high efficiencies and can be processed very cost-effectively from solution as extremely thin layers. However, perovskite-based solar cells are not yet stable enough to be commercialised.
Consensus on protocols
Now, international experts from 51 research institutes under the leadership of Prof. Mónica Lira-Cantú (Institut Catala de Nanosciencia i Nanotechnologia) and Prof. Eugene A. Katz (Ben-Gurion University of the Negev) have agreed on the ageing protocols suitable for this class of materials. From the Helmholtz-Zentrum Berlin, Prof. Antonio Abate and his PhD student Hans Köbler were involved. The first author of the study, Dr. Mark Khenkin, is now also working as a postdoc at the HZB Institute PVcomB. Eugene Katz will soon complete a longer research stay at HZB. The consensus statement extends the ISOS protocols developed in 2011 for organic solar cells for the stability assessment of perovskite photovoltaics by further tests and parameters. The test procedures are tailored to the specific characteristics of perovskite solar cells and can thus also map their special properties.
Step forward to industrialisation
In particular, the consensus allows for better comparability of ageing data between international laboratories and thus promotes meaningful analyses of degradation processes. A checklist for reporting the results should further improve reproducibility. This is a major milestone on the way from the laboratory to industry, writes Nature Energy in an editorial to the publication, which has now even been highlighted by the European Commission.
The consensus statement is published in Nature Energy 2020: "Consensus statement for stability assessment and reporting for perovskite photovoltaics based on ISOS procedures".
DOI: 10.1038/s41560-019-0529-5
Editorial in Nature (2020): "Perovskites take steps to industrialization"
Highlight EU Science Hub: "Perovskite PV technology approaches industrialisation as researchers reach consensus on procedures for testing it"
- Thin nickel films boost green hydrogen productionUltra-thin nickel oxide coatings can significantly improve the performance of anion exchange membrane (AEM) water electrolysers, a promising technology for producing green hydrogen. This was demonstrated by a team led by HZB scientist Dr. Michelle Browne. The results show that a nickel oxide film only 10 nanometres thick outperformed conventional nickel oxide powder electrodes while using less than 1% of the catalyst material. The study is published in the Journal of Materials Chemistry A,
- Detailed insights at BESSY II into the oxidation processes of copperBefore pure copper oxide builds up, complex superstructures such as ‘29’CuxO, are formed. The new results on the '29' CuxO superstructure have relevance for catalyst research and corrosion protection in the development of safe copper containers for nuclear waste repositories.
- BESSY II: Evaporated perovskites in tandem solar cells improvedPerovskite-silicon tandem solar cells achieve significantly higher efficiencies than silicon solar cells on their own. One particularly attractive method is co-evaporation of the perovskite precursor molecules on top of the silicon subcell. Scientists at HZB have analysed film growth on the nanoscale at BESSY II and found a new way to improve the quality of the perovskite layer: adding a thin seed layer of caesium chloride between the two sub-cells promotes uniform perovskite growth and suppresses the formation of undesired lead iodide at the interface.