Two high-efficiency PV technologies rolled into high-efficiency module

Oxford PV and the Fraunhofer Institute for Solar Energy Systems (ISE) have worked together to combine two high-efficiency technologies in a single photovoltaic module. They used perovskite-silicon solar cells from Oxford PV and connected them using the Matrix Shingle technology developed by ISE. Oxford PV was the first company to bring perovskite-silicon tandem technology into industrial production.

The new module design will be on display for the first time at The Smarter E / Intersolar trade fair, taking place from 23-25 June 2026 in Munich, Germany. A rooftop module variant is on display at Fraunhofer ISE’s stand in hall A1.440, and a bifacial module for large-scale ground-mounted installations is shown at Oxford PV’s stand in hall A4.540.

Prof Dr Stefan Glunz, Head of Photovoltaics at ISE, commented, “We cut the solar cells from Oxford PV into shingles, arranged them in a matrix structure, electrically connected them using conductive adhesive, and then encapsulated them.” The tandem modules are of a glass-glass format with edge sealing to protect the moisture-sensitive solar cells.

The 491-watt rooftop module has an area of 1.92 square meters, whilst the large-area, 546-watt bifacial module covers 2.13 square meters. Both achieved an efficiency of 25.6 percent across the entire module area.

“Our tandem technology and the shingle interconnection work well together technologically. Due to the lower current densities of the perovskite-silicon solar cells, they can be cut into wider strips, which increases productivity,” said Dr. Ed Crossland, CTO at Oxford PV. Tandem solar cells achieve significantly higher voltages and efficiencies than conventional cells, while the current is lower due to its distribution across two sub-cells. This lower current density helps reduce resistive losses within the PV module.

“At the same time, the adhesive interconnection of the Matrix shingle technology is a low-temperature process and requires no copper connectors,” said Crossland. Using fewer copper connectors can cut operating costs and reduce stresses in the module construction.

Boosted efficiency

Tandem solar cells have the potential to significantly boost efficiency in photovoltaics: by applying a perovskite cell just a few hundred nanometres thick onto a conventional silicon solar cell, the theoretical efficiency limit rises from 29.4 to 43.3 percent, say the partners.

Oxford PV’s perovskite-silicon solar cells and modules are manufactured in a pilot production facility in Brandenburg an der Havel, Germany. The perovskite cell is applied directly onto a silicon heterojunction cell using thin-film processes.

In Matrix-Shingle technology, the solar cell strips are bonded together using 100 percent lead-free, electrically conductive adhesives, with the strips arranged in an overlapping and staggered pattern like shingles. This enables complete, homogeneous coverage of the entire module surface. Furthermore, Matrix-Shingle technology is characterised by a high tolerance to partial shading. With the matrix arrangement, the current can flow around the shaded areas, meaning that, depending on the degree of partial shading, twice the power can be generated compared to conventional inter-connected PV modules.

The new PV modules were developed as part of the ‘HoTSun’ research project, funded by Germany’s Federal Ministry for Economic Affairs and Energy (BMWE).