Researchers from the University of Cadiz, the University of Valencia, and the University of Bordeaux have been investigating the effects of temperature and excitation power on the down-conversion process in silica-hafnia glass-ceramic films activated with rare earth ions. Their work, published in the journal Optical Materials, focuses on the potential of these materials to enhance the efficiency of photovoltaic systems.
Transparent glass ceramics activated with rare earth ions are known to be excellent photonic materials. Among these, silica-hafnia binary systems have shown great promise as matrices for incorporating rare earth ions into hafnia nanocrystals. This incorporation leads to significant luminescence enhancement, opening up a wide range of critical applications. The researchers focused on the down-conversion mechanism driven by the couple Tb3+/Yb3+, which is particularly relevant for photovoltaic systems.
The study was conducted on silica-hafnia glass-ceramic films activated with 19% rare earth ions. Two main findings were discussed. First, the intensity and broadening of the Yb3+ emission band at 975 nm were found to be temperature-dependent. This means that the efficiency of the down-conversion process can be influenced by the operating temperature of the photovoltaic system.
Second, the researchers delved into the energy transfer mechanism from Tb3+ to Yb3+. They discussed various mechanisms proposed in the literature and analyzed the power dependence spectra for the luminescence of Yb3+. Understanding this mechanism is crucial for optimizing the design of photovoltaic systems to maximize their efficiency.
The practical applications of this research are significant for the energy sector, particularly in the field of solar energy. By enhancing the down-conversion process, these materials can help improve the efficiency of photovoltaic systems, making solar energy a more viable and competitive option. The findings also contribute to the broader understanding of photonic materials and their potential applications in various energy technologies.
Source: Amrani, S. E., Sun, M., Valdueza-Felip, S., Naranjo, F. B., Britel, M. R., Ferrari, M., & Bouajaj, A. (2023). Effect of temperature and excitation power on down-conversion process in Tb3+/Yb3+-activated silica-hafnia glass-ceramic films. Optical Materials, 134, 113402.
This article is based on research available at arXiv.