Perovskite solar cells show great promise as renewable energy sources, are relatively cheap and simple to manufacture, and have reached power conversion efficiencies (PCEs) of over 21 %. However, there are still issues preventing their widespread use, such as insufficient structural and thermal stability as well as moisture sensitivity.
Michael Saliba, École Polytechnique Fédérale de Lausanne, Switzerland, and colleagues have improved on the currently best-performing perovskites, which contain organic methylammonium (MA, CH3NH3+) and formamidinium (FA, CH3(NH2)2+) cations, by adding small amounts of cesium. The new triple cation perovskite avoids both the drawbacks of FA/MA perovskites, namely poor structural and thermal stability, and those of pure cesium lead trihalides, which has a nonideal band gap and a photoinactive “yellow phase” at temperatures under 300 °C.
The researchers tested the material in solar cells, and found efficiencies of up to 21.1 %, even after 250 hours of continued use. The triple cation perovskite films could be more reliably manufactured with less variability and impurities than the MA/FA materials. According to the team, such cation mixtures are a promising strategy for the industrialization of perovskite solar cells with better stability and reproducible high efficiency.
- Cesium-containing Triple Cation Perovskite Solar Cells: Improved Stability, Reproducibility and High Efficiency,
Michael Saliba, Taisuke Matsui, Ji-Youn Seo, Konrad Domanski, Juan-Pablo Correa-Baena, Nazeeruddin, Mohammad K., Shaik M Zakeeruddin, Wolfgang Tress, Antonio Abate, Anders Hagfeldt, Michael Grätzel,
Energy Environ. Sci. 2016.
DOI: 10.1039/c5ee03874j
Also of Interest
- The Promise of Perovskite,
David Bradley,
ChemViews Mag. 2015.
DOI: 10.1002/chemv.201500029
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