Ultra-efficient perovskite-silicon tandem solar cells

Dual-junction perovskite–silicon tandem solar cells have surpassed the theoretical efficiency limits of single-junction photovoltaic devices, establishing themselves as one of the most promising platforms for next-generation solar energy conversion. Despite this progress, key scientific and technological challenges remain in achieving simultaneously high efficiency, long-term stability, and scalable device architectures.

Our research focuses on addressing these challenges through a comprehensive investigation of tandem solar cell concepts, spanning two-terminal (2T) and four-terminal (4T) configurations, as well as emerging approaches such as beyond dual-junction tandems (e.g., triple junctions) and bifacial tandem architectures. Across all concepts, our central objective is to maximize real-world energy yield while ensuring operational stability and reliability.

A major thrust of our work lies in the materials science of wide-bandgap perovskites, where we investigate composition inhomogeneities, strain- and stress-induced effects, and their impact on voltage losses, phase stability, and device degradation. By correlating microscopic material properties with optoelectronic device performance, we establish design principles for robust and efficient tandem absorbers and interfaces.

Beyond cell-level performance, our group places strong emphasis on stability assessment and reliability testing. We implement and critically evaluate advanced aging protocols relevant to tandem devices, including IEC- and ISOS-defined tests such as damp heat, thermal cycling, maximum power point tracking (MPPT) at elevated temperatures, and potential-induced degradation (PID). In parallel, we investigate module packaging and encapsulation strategies, recognizing their decisive role in enabling long-term operation under realistic environmental conditions.

Our research is conducted at the interface of fundamental understanding and technological relevance, with the aim of accelerating the transition of perovskite–silicon tandems from laboratory-scale demonstrations to reliable photovoltaic modules. To this end, we collaborate closely with leading universities, research institutes, international consortia, and industrial partners worldwide, contributing to the scientific foundations and practical solutions required for the industrialization of perovskite–silicon tandem solar cells.