Highly efficient up-conversion luminescence in BaCl₂:Er³⁺phosphors via simultaneous multiwavelength excitation

Abstract

It has been observed that BaCl2:Er3+ phosphors have a higher up-conversion luminescence efficiency than the well-known fluoride regarded widely as the most efficient up-conversion host material. The near-infrared-to-visible up-conversion luminescence is markedly enhanced for BaCl2:Er3+ phosphors when excited simultaneously at two wavelengths (808 and 980 nm) in contrast to the case of single-wavelength excitation. Furthermore, our results demonstrate that the multiwavelength simultaneously excited up-conversion process in BaCl2:Er3+ phosphors allows better and broader harvesting of near-infrared solar energy, which is expected to open the possibilities of the remarkable improvement of the power conversion efficiency of next-generation solar cells.