A team led by the University of New South Wales (UNSW) and others is advancing a solar-cell strategy that combines traditional silicon with an organic “singlet-fission” layer, tells Tech Xplore. The approach targets a key inefficiency in standard silicon PV systems: a large portion of sunlight is absorbed, but the high-energy photons lose excess energy as heat rather than generating additional current.
In standard silicon cells, the best commercial efficiencies hover near 27%, and the theoretical limit is around 29.4% for single-junction silicon. The innovation described places a specially selected organic layer over the silicon. When a high-energy photon hits the organic material, it triggers “singlet-fission”—generating two lower-energy excitons (i.e., pairs of charge carriers) from one photon. In effect, one photon becomes two usable excitations. This mechanism aims to boost the overall current output beyond what silicon alone allows.
Project lead Ned Ekins-Daukes highlights that the integration of this organic layer into silicon-based devices is the next step. The UNSW team reports that embedding this layer over silicon could significantly increase energy conversion by capturing photons that would otherwise be wasted. They emphasize that the current research is at the proof-of-concept stage: materials development, interface compatibility, and integration into existing silicon PV manufacturing remain major tasks.
The work points toward tandem-style cell architectures that preserve the manufacturing base of silicon while adding a front-end boost layer. The broader implication: rising module efficiencies and better utilization of the solar spectrum could reduce land-use, materials intensity, and cost per watt for solar systems. But commercial viability will depend on scale-up, stability of organic materials, and cost-effectiveness in mass production.