Upconverting ultraviolet light source with extended emission wavelengths based on Bi3+-activated phosphor.

Upconverted ultraviolet luminescence technology is attracting extensive interest lately due to its potential applications. To date, visible-to-ultraviolet upconversion has been achieved in Pr3+, Gd3+, Er3+, Ho3+ or Tm3+-activated phosphors. We herein report an upconverted ultraviolet emission of Bi3+ in a co-doped phosphor, YBO 3 :Pr3+,Bi3+, utilizing a 447 nm laser for excitation. Through spectroscopic investigations, we have determined that the blue laser excites the Pr3+ 4f5d state, followed by an energy transfer to the excited state of the Bi3+ ion in the phosphor. Consequently, the upconverted emission spectra do not show the Pr3+ (4f5d→4f2) emission, but rather the ultraviolet emission is completely dominated by the Bi3+ (3P 1 →1S 0) emission. Taking advantage of the ultraviolet emission performance and blue light excitability of the phosphor, we have successfully built and demonstrated a prototype upconverting ultraviolet light source based on phosphor conversion. The introduction of Bi3+-activated upconversion luminescence enriches the bank of upconverting ultraviolet phosphors and provides a novel upconversion strategy for achieving Bi3+-activated ultraviolet light source. • Achievement of visible-to-ultraviolet upconverted emission from Bi3+ ion. • Energy transfer mechanism from Pr3+ to Bi3+ in YBO 3 :Pr3+,Bi3+. • Development of a prototype upconverting ultraviolet light source based on phosphor conversion. [ABSTRACT FROM AUTHOR]