Luminescent Solar Panel Coatings
A luminescent materials that can cut one high energy photon into two lower energy photons can break the well-known Shockley-Queisser limit of solar cells. A luminescent coating on the glass plate covering the solar panel can enhance efficiency up to a factor of 1,2 in a cost-effective way without changing the solar cell itself. This would be a worthy large step in the field of PV. Finding such a photon multiplying material is a holy grail in luminescence materials research.
Two-step energy transfer
The challenge is to absorb all solar light with an energy higher than two times the band-gap of the solar cells by a first ion and successively transfer part of the the energy to a neighboring second ion. After this energy transfer step, both ions can emit a photon with an energy close to the band-gap of the cell. This energy transfer approach has been successful by combining two rare earth ions, but optimized phosphors of that type have never reached external quantum efficiencies above 100%. We are exploring new avenues to find the ultimate down-converting material.