A silicon cell responds across the visible spectrum, but the complete module converts near-ultraviolet poorly. High-energy photons lose much of their energy to heat.
Ultraviolet exposure is also one of the drivers of polymer ageing in the module. SolaGro's film intercepts that ultraviolet and re-emits it lower down the spectrum.
Luminophores dispersed in the film absorb high-energy ultraviolet photons before they reach the cell.
Each absorbed photon is re-emitted at a longer wavelength, in the blue. This is down-conversion: one photon in, one photon out, shifted into the part of the spectrum silicon handles well.
The cell receives photons shifted into a wavelength region where its spectral response is stronger.
The module also sees less ultraviolet, which may slow ultraviolet-driven ageing. Yield decline has several causes, and this addresses one of them.
A field hypothesis worth testing. Scattered skylight is relatively rich in short wavelengths, because Rayleigh scattering rises steeply as wavelength falls. So the band this film addresses is a larger share of what is available when the diffuse fraction is high.
Whether that produces a larger relative electrical gain is unproven, and it is a field-validation question rather than a claim. It is one of the things the trials are designed to answer.
Most optical down-conversion materials in solar are borrowed from display and lighting chemistry: quantum dots, rare-earth phosphors, organic dyes based on extended fused-aromatic systems, and photonic or perovskite coatings.
Each buys photon conversion at a price: toxicity, critical-mineral dependence, or susceptibility to photodegradation.
Ours came out of a different starting point. The programme began with the discovery of ultraviolet down-conversion, including non-traditional intrinsic luminescence, in aliphatic amino-acid-derived Guerbet surfactants.
Structure-property optimisation then identified an ortho-aminobenzoic-acid-derived Guerbet surfactant as the lead photovoltaic luminophore. That is the material in the film today.
It carries an aromatic aminobenzoic-acid luminophore, so it is not dye-free. What it is free of is heavy metals and rare earths, and it is distinct from extended fused-aromatic dyes, semiconductor quantum dots and phosphors. As far as we and our patent attorneys can establish, the platform and its photovoltaic application are new.
The PMMA film is applied to the outside of the module glass, held by electrostatic interaction rather than permanent adhesive bonding. That minimises intervention in the module laminate and the edge seal.
This route reaches the installed base, which no cell-level improvement can do. Warranty and certification acceptance remain matters to be agreed with manufacturers and asset owners.
For new build, carrying the active in the encapsulant is technically plausible and not yet validated. Modern modules use glass and encapsulation systems that already manage ultraviolet, so the optical stack may need to be redesigned around the film rather than the film simply added to it.
Thermogravimetric analysis puts the onset of degradation at about 350 degrees Celsius, with substantial decomposition by about 370. Against a standard lamination step at 180, that is real thermal headroom for conventional polymer processing.
This is a co-development route with an OEM, not a drop-in.
The film acts on the incoming spectrum rather than on the cell junction, so it is additive to whichever cell architecture prevails.
We are not competing with PERC, TOPCon, heterojunction or perovskite tandems. We sit in front of all of them.
Our own measurements are our own.
Independent cross-laboratory verification of both efficiency and photostability, and field data from operating installations, are part of the development programme rather than claims we make ahead of it.
There is a measurement problem underneath this. Our laboratory simulator provides a controlled reference spectrum at normal incidence. It does not reproduce the changing spectral and angular composition of diffuse outdoor irradiance, and it offers no way to vary the diffuse fraction.
Modules are also procured on peak watts at standard test conditions, while the standardised route that would capture behaviour across real climates is energy rating under IEC 61853, which is rarely specified commercially.
Field trials are therefore essential rather than confirmatory: they are how we test whether the relative gain changes under real sky conditions.
The technology sits at TRL 4: a laboratory prototype, validated. The route to TRL 7 is defined and runs in three tracks. An R5.9m Product Development Fund application is in the final review stages at South Africa's Technology Innovation Agency, and pre-seed capital is being prepared alongside it.
From 20 gram towards 10 kilogram batches in a flow reactor, with a documented and validated procedure and a quality-control protocol that holds across batches. The 10 kilogram figure is a programme target.
Best-fit polymer matrix, formulation and concentration, with production infrastructure for film manufacture at industrially meaningful quantities.
Long-term monitoring on operating installations, plus independent cross-laboratory verification of efficiency and stability at third-party commercial facilities.
The same emitter chemistry has adjacencies we have not chased but which keep finding us: ultraviolet filtering, agricultural glazing, and blue emission for display and lighting applications.
A direct-photovoltaic water-heating company approached us to trial the film on solar thermal collectors, which is a second application in a market we did not design for.
Solar photovoltaics is the beachhead. It is not the ceiling.
We are looking for industrial partners, module manufacturers and validation facilities.