Sr₂CeO₄ dopado com terras raras como potencial sistema para melhor eficiência em energia solar

Abstract

The growing demand for research focused on efficient solar energy conversion has driven the development of new luminescent materials capable of optimizing the capture and utilization of the solar spectrum. In this context, the Sr₂CeO₄ matrix doped with rare-earth ions such as Er³⁺ and Yb³⁺ stands out due to its Upconversion and Downshifting properties, which are crucial for photovoltaic applications. In the present work, the Pechini method was employed to synthesize the Sr₂CeO₄ matrix doped with erbium and ytterbium ions. Following oven drying and subsequent thermal treatment at 1200 °C, morphological and spectroscopic characterizations were carried out, which confirmed the formation of the orthorhombic Sr₂CeO₄ phase as the product of the treatment. Through FTIR analyses, characteristic bands of the target material were identified, including angular deformations of Sr–O and Ce–O bonds associated with the Sr₂CeO₄ phase. The upconversion phenomenon enables the conversion of low-energy photons (such as those in the near-infrared range) into higher-energy photons, thereby enhancing the efficiency of solar cells by harnessing radiation that would otherwise be dissipated. Simultaneously, downshifting reduces thermal recombination losses by converting high-energy photons into photons with energy levels more suitable for operational absorption by solar cells. In this process, codoping with Yb³⁺ and Er³⁺ plays a key role: Yb³⁺ acts as a sensitizer, absorbing light at 980 nm and transferring energy to Er³⁺, which emits in the visible region of the spectrum. Thus, the combination of these optical properties makes Sr₂CeO₄-based materials doped with rare-earth ions promising candidates for improving the efficiency of renewable energy devices, contributing to sustainable advancements in clean energy generation.