Luminescent materials have two truly unique properties that make them ideally suited for application as coating on glass to make electricity generating windows. They are able to spectrally concentrate a wide range of the solar spectrum to a single wavelength, and they are able to spatially concentrate this light, without the use of lenses or mirrors, to a narrow surface area. These two properties can be combined in a so-called Luminescent Solar Concentrator (LSC) that consists of a luminescent coating on glass that absorbs part of the solar spectrum and re-emits this energy in the form of luminescence that is trapped, just like in a fibre optical cable, and can only escape at the edges of the glass window where strip shaped solar cells convert the light into electricity.
Current work involves tackling many scientific challenges like understanding (i) the rare earth valence stability, (ii) the 5d energy level splitting and location, (iii) the formation of thin-film solid solutions, (iv) defect formation and rare earth solubility, (v) combinatorial reactive co-sputtering of thin-films.
The realization of record-braking LSC prototypes is one of the more technological challenges.