Highly-doped lanthanide nanomaterials for efficient photothermal conversion – selection of the most promising ions and matrices

Materials doped with rare earth ions are widely used in luminescence applications. However, alternative uses of these materials, such as photothermal conversion, have not yet been systematically investigated. In this work, we systematically and quantitatively compare internal and external photothermal conversion efficiency of materials doped with neodymium, thulium and ytterbium ions, and co-doped with samarium and dysprosium ions. Furthermore, we investigate influence of various matrix materials on photothermal conversion efficiency. These include fluoride, oxide, vanadate and perovskite materials. This was done to determine if photothermal conversion efficiency is dependent on dopant and matrix selection. Our research indicates that the highest internal and external photothermal conversion efficiency is achieved with neodymium ions. Moreover, NdVO4 was found to be the most promising host for future applications. Although the internal photothermal conversion efficiency was relatively low (19%), NdVO4 exhibited significant external photothermal conversion efficiency of 0.08 L/g·cm at 806 nm, which is ca. 14 times higher than that of NaNdF4 at the same wavelength.