Improvements in perovskite solar cells may propel this photovoltaic technology ahead of silicon solar cells in Perovskite solar cell prototype. Source: Alain Herzog / EPFLterms of efficiency. However, stability remains a challenge: perovskites are soft crystalline materials and prone to decomposition-related issues over time. Stability limitations can render perovskites less economically attractive than conventional silicon cells.

A large cation solution that can boost both efficiency and stability is reported by an international team of researchers. Introducing guanidinium cations into the crystal structure of methylammonium lead iodide perovskites enhances the material’s overall thermal and environmental stability.

The inclusion of guanidinium improves perovskite stability while delivering an average power conversion efficiency over 19 percent. This performance is stabilized for 1,000 hours under continuous light illumination, which is a standard laboratory test for measuring the efficiency of photovoltaic materials. The researchers estimate that this corresponds to 1,333 days (or 3.7 years) of real-world usage.

Scientists from Ecole Polytechnique Fédérale de Lausanne (EPFL) in Switzerland; Universidad de Córdoba in Spain; Abengoa Research in Spain; Humboldt-Universität zu Berlin in Germany and Helmholtz-Zentrum Berlin für Materialien und Energie in Germany participated in this research.