In the realm of energy research, a team of scientists from the Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS) in France, led by Damien Rinnert and Emmanuel Drouard, has made a significant stride in the field of upconversion luminescence. This technology has potential applications in solar energy conversion and environmental cleanup.
Upconversion luminescence is a process where low-energy photons are absorbed and then re-emitted as higher-energy photons. Traditionally, this has been studied using lanthanide materials to convert near-infrared light into visible light. However, converting a broad spectrum of light into ultraviolet (UV) light has been less explored, despite its potential for applications like solar-to-fuel conversion and environmental remediation.
The researchers engineered photonic crystals to assist in this multi-wavelength upconversion process. Photonic crystals are materials with a periodic optical nanostructure, which affects the motion of photons, much like a semiconductor affects the motion of electrons. By carefully designing these structures, the team was able to enhance the absorption of visible light and the extraction of UV light, resulting in a 28-fold increase in UV upconversion luminescence in Yb3+-Tm3+ doped thin films.
The team optimized the materials and geometric parameters of the photonic crystals to minimize parasitic absorption losses and match a slow-light resonance with an excited-state transition of Tm3+. This enhancement of incident visible light absorption, along with the enhanced UV light extraction, was quantified and validated through electromagnetic simulations. The research was published in the journal Nature Communications.
This advancement could have practical applications in the energy sector, particularly in improving the efficiency of solar cells and other solar energy conversion technologies. By converting more of the solar spectrum into useful UV light, these technologies could potentially become more efficient and cost-effective. Additionally, the enhanced UV light output could be used for environmental remediation, such as water purification and air cleaning.
This article is based on research available at arXiv.