Cambridge Photon Technology

Cambridge Photon Technology (CPT) is a deep-tech spinout from the University of Cambridge developing a patented photon-multiplier material that boosts the output of existing silicon solar panels by up to 15%, without requiring any change to panel design or manufacturing process. The company was founded by CEO Dr Claudio Marinelli, Professor Hugo Bronstein, and Professor Akshay Rao, all from the University of Cambridge, and is supported by Cambridge Enterprise Ventures.

Silicon photovoltaics have become the cheapest source of electricity generation in history, but the physics of silicon imposes a hard ceiling on how much of the sun's light a standard panel can convert to electricity. A significant portion of incoming sunlight — particularly high-energy blue and ultraviolet photons — cannot be efficiently absorbed by silicon and is instead lost as heat. This spectral loss is one of the most significant efficiency gaps in conventional solar PV and has proven difficult to address without redesigning the cell architecture or adopting complex and capital-intensive tandem approaches such as perovskite-silicon stacks.

CPT's photon-multiplier technology addresses this directly. Its patented material, applied as a coating to existing solar module assembly lines, absorbs high-energy photons and re-emits each one as two lower-energy infrared photons that silicon can efficiently capture. Because the material integrates as a drop-in coating step into standard module production, manufacturers can adopt it without retooling, additional capital expenditure, or changes to panel design. The company describes it as the first demonstrated photon-multiplication effect at scale in a commercially viable format.

Cambridge Photon Technology raised £1.56 million in a pre-Series A round in November 2025, comprising £926,000 in equity from Cambridge Enterprise Ventures, Spectrum Impact, Tybourne Capital, Providence Investment Company, and SourceSquared, alongside a £630,000 Innovate UK grant. The capital will fund R&D expansion in Cambridge, accelerated testing with global solar industry partners, and preparation for a larger Series A ahead of pilot commercial deployment. The company is targeting its first commercial product by 2028.