Perovskites: the future of PV? - The smarter-E Podcast
Perovskites: The Race for the Future of PV?
The smarter E Podcast Episode 258 | 25 June 2026 | Language: English
This episode, which was recorded in June 2026 at the “Tandem PV Workshop” in Berlin, explores one of the most exciting areas of research in solar technology: perovskite-based tandem photovoltaics. In this discussion, Rutger Schlatmann and Angelika Harter explain why perovskites could enable the next major step towards higher solar efficiency – and what still needs to happen before the technology reaches commercial mass production.
The first part addresses the question of why silicon-perovskite tandem solar cells are of such interest to researchers and industry. Rutger Schlatmann explains how conventional silicon technology is reaching its physical efficiency limits and why applying a perovskite layer to silicon opens up a path to significantly higher output.
In the second half of the episode, Angelika Harter discusses the transition from record-breaking laboratory results to commercially viable solar products. She reports on insights from the ‘Tandem PV Workshop’ recently held in Berlin, where the industry’s focus is increasingly shifting from simply achieving higher efficiencies towards understanding and improving stability, scalability and reproducibility.
In addition, journalist Jonathan Gifford and the two HZB colleagues discuss new possibilities for perovskite technologies beyond conventional solar modules – including flexible PV, indoor applications and space technologies – and explore why the next five years could be crucial for bringing the first generation of commercial perovskite products to market.
- CIGS-perovskite tandem cell achieves record efficiency of 25.5 %A Berlin-based team from HZB and Center for the Science of Materials Berlin (CSMB) at the Humboldt-Universität zu Berlin has set a new record for a tandem solar cell. Using a combination of a CIGS semiconductor layer and perovskite, along with several optimised intermediate layers, they were able to convert 25.5% of sunlight into electrical energy. The previous record for this combination of materials and this size of cell stood at 24.6%. The new record has been certified and is visible in the prestigious Solar Cell Efficiency Tables (the "Green Tables"), which serve as the definitive ledger for the global photovoltaic community.
- Disorder creates new properties in compound semiconductorsAn international research team has demonstrated that the intrinsic disorder of the compound semiconductor CuInSnS₄ can be exploited to influence its optical properties. While the atomic vibrations also sense the local disorder, their response is averaged over many different local environments and therefore appear isotropic, as expected for a cubic crystal. In contrast, the optical excitations, known as excitons, are much more sensitive to the local arrangement of atoms. Surprisingly, they show a direction-dependent optical response even though the average crystal structure is cubic. These findings shed new light on the relationship between disorder and material properties, opening up new options for targeted 'disorder engineering' in optoelectronic and photocatalytic devices.
- Perovskite solar cells: Predictions of long-term stabilityReliable statements about the long-term stability of perovskite solar cells are still difficult to make. However, a new study by Dr Carolin Ulbrich’s team, published in the renowned journal Joule, highlights which methods are useful for this purpose and identifies areas where further research is needed.