The concept of quantum cutting solar concentrator is proposed, which can double the efficiency of fluorescent solar concentrator.

Fluorescent solar concentrator is a large-area solar energy capture device with relatively simple structure, which is composed of luminescent groups coated or embedded in a transparent substrate. The luminous body emits photons after absorbing solar photons incident on the panel. Due to the refractive index difference between the substrate and the air, about 75% of photons will generate total reflection mode, which will be guided to the edge of the panel to excite the solar cells attached to the edge. If the concentrating efficiency is high enough, a fluorescent solar concentrator with several solar cells on the edge can be functionally equivalent to a large-area solar cell, which will greatly reduce the cost of photovoltaic capacity. However, the traditional fluorescent solar concentrator is limited by the low fluorescence efficiency and self-absorption loss of fluorophores, resulting in the internal optical efficiency of the device is generally lower than 60%.

Quantum clipping is a novel optical phenomenon. The material based on this effect can absorb one high-energy photon and release two low-energy photons at the same time, which satisfies the basic physical law of energy conservation. The research team creatively proposed a fluorescent solar concentrator based on quantum clipping effect, which can theoretically double the fluorescence quantum efficiency and completely suppress the self-absorption loss. Therefore, the internal optical efficiency of solar concentrator can redefine a new theoretical limit-150%.

Based on this concept, the research team synthesized a rare earth ytterbium-doped nanocrystalline material with typical quantum tailoring characteristics, and made a prototype quantum tailoring fluorescent solar concentrator with an internal optical efficiency of about 1.20%. In this study, the concept of "quantum cutting solar concentrator" is put forward for the first time, which has broad application prospects in reducing photovoltaic costs and realizing intelligent buildings.