Full text loading...
NIR PL spectra of NaYF4:Tm3+ and NaYF4:Tm3+, Yb3+, respectively. Solid lines are PL spectra recorded on a R5509-72 PMT, and dotted line represents those which were measured with a PbSe detector. The inset of (a) shows visible PL spectrum of NaYF4:Tm3+ excited at 470 nm.
PLE spectra of NaYF4:Tm3+ monitored at PL wavelengths of 646, 804, 1165, 1466, and 1800 nm, respectively. Solid PLE spectra are recorded on a R5509-72 PMT, and dotted measured with a PbSe detector.
Energy-level diagrams presenting the concept of a sequential three-step three-photon NIR QS: (a) for NaYF4:Tm3+ excited by 470 and 798 nm, and (b) for a 976 nm LD pumping Yb3+ to excite Tm3+ through a Stokes ET in NaYF4:Tm3+,Yb3+. (1) the first-step, 1G4 → 3H4 at 1165 nm, (2) the second-step, 3H4 → 3F4 at 1466 nm, and (3) the third-step, 3F4 → 3H6 at 1800 nm. Solid and dotted arrows represent optical transition and NR processes, respectively.
Time-resolved emission spectra of NaYF4:Tm3+ with delay times 112, 152, 360, 700, 1100, and 1800 μs in the 1100 and 1700 nm wavelength range upon 470 nm pulsed excitation with a μF900 microsecond Xe flashlamp.
Article metrics loading...