Technical University of Munich Researchers Develop Breakthrough Method to Improve Stability of Perovskite Solar Cells for Real-World Use

Dr. Yuxin Liang / TUM / Dr. Kun Sun is holding a perovskite solar cell.

(IN BRIEF) Researchers from the Technical University of Munich and international partners including KIT, DESY, and KTH have identified the root cause of performance degradation in perovskite solar cells during thermal cycling and developed a stabilisation method using molecular “anchors,” with findings showing that a significant portion of efficiency loss occurs during an early burn-in phase caused by internal structural stress, while the introduction of robust organic molecules such as PDMA helps maintain crystal integrity and significantly improves durability, paving the way for more reliable, high-efficiency tandem solar cells capable of withstanding real-world environmental conditions and supporting long-term solar energy deployment.

(PRESS RELEASE) MUNICH, 27-Mar-2026 — /EuropaWire/ — Technical University of Munich researchers, working within the e-conversion Cluster of Excellence and alongside international partners, have identified the underlying causes of degradation in perovskite solar cells and introduced a method to significantly improve their durability under real-world conditions.

Perovskite solar cells are widely regarded as a transformative technology in photovoltaics due to their exceptional efficiency and potential to lower solar energy costs. However, their vulnerability to temperature fluctuations has limited their commercial deployment. In collaboration with Karlsruhe Institute of Technology, DESY, and KTH Royal Institute of Technology, the research team investigated how these materials behave under thermal stress and developed a stabilisation approach based on molecular engineering.

A key challenge for perovskite solar cells is their exposure to thermal cycling, where temperatures can shift dramatically between day and night. These repeated fluctuations cause structural strain within the material, leading to performance loss. To better understand this phenomenon, the team analysed the microscopic changes occurring during these cycles, focusing particularly on wide-bandgap perovskite cells used in tandem solar cell configurations.

Prof. Peter Müller-Buschbaum and his team demonstrated that the most significant degradation occurs during an early operational stage known as the “burn-in” phase. During this period, solar cells can lose a substantial portion of their efficiency as internal mechanical stress disrupts the crystal structure. Using high-resolution X-ray techniques at DESY, the researchers observed how the material expands and contracts under temperature changes, revealing a dynamic structural instability that directly impacts performance.

Lead researcher Dr. Kun Sun explained that this initial degradation is driven by internal tension within the material, which alters its structure and reduces energy output. By identifying this mechanism, the team has provided a clear pathway for improving long-term stability by addressing the burn-in phase.

Building on these findings, the researchers developed a strategy to reinforce the material using specially designed organic molecules that act as stabilising agents. These molecules function as structural supports, maintaining the integrity of the crystal lattice during temperature changes. Among the tested compounds, a bulkier molecule known as PDMA proved particularly effective, significantly enhancing the resilience of the solar cells.

This innovation enables perovskite solar cells to better withstand the mechanical stress associated with real-world operating conditions, making them more suitable for long-term outdoor use. The improved stability is especially important for tandem solar cells, which combine multiple layers to maximise energy conversion efficiency.

The research findings were published in Nature Communications and ACS Energy Letters, highlighting both the discovery of the degradation mechanism and the proposed stabilisation solution.

By addressing one of the most significant barriers to commercialisation, this work advances the development of next-generation solar technologies. The researchers emphasise that enhancing both efficiency and durability is essential for ensuring that perovskite-based solar systems can meet long-term climate and energy goals.

Publications

Kun Sun, Renjun Guo et al.: “Insights into the operational stability of wide-bandgap perovskite and tandem solar cells under rapid thermal cycling”, published in: Nature Communications, 14 January 2026, DOI: https://doi.org/10.1038/s41467-025-68219-w

Kun Sun, et al.: “Halide Segregation in Wide-Bandgap Quasi-2D Perovskites under Rapid Thermal Cycling”, published in: ACS Energy Lett. 2026, 11, 3, 2952–2958, 24 February 2026, DOI: https://doi.org/10.1021/acsenergylett.6c00094