Efficiency enhancement of photovoltaic cells under infrared light irradiation by synergistic upconversion luminescence of NaYF4:Yb3+/Er3+/Tm3+@TiO2-CQDs

Abstract

Rare-earth doped upconversion luminescence (UCL) is of great significance in improving the utilization of infrared (IR) light from solar radiation, especially in the efficiency enhancement of photovoltaic (PV) cells. However, the low level of luminescence efficiency remains a great challenge. Here, we designed NaYF₄:Yb³⁺/Er³⁺/Tm³⁺@TiO₂-CQDs upconversion luminescent materials. The construction of the core–shell structure and the loading of carbon quantum dots (CQDs) resulted in a 9-fold enhancement of upconversion luminescence and a 3.02% enhancement of the efficiency of the photovoltaic cell. These data indicate that the construction of the core–shell structure can effectively inhibit the surface quenching of the luminescent particles, and that the energy transfer between the carbon quantum dots and the rare earth ions has a synergistic effect on the efficiency enhancement of the photovoltaic cell. Meanwhile, the TiO₂ shell layer also enables the prepared materials to have better properties of self-cleaning and degradation of organic pollutants, which will further improve the visible light utilization of PV cells. NaYF₄:Yb³⁺/Er³⁺/Tm³⁺@TiO₂-CQDs provides new ideas for the practical application of PV cell efficiency enhancement and the design of new materials.