Abstract
Near-infrared (NIR) laser excitation into the Yb3+2F7/2→2F5/2 absorption transition around 10,200cm−1 at 12K leads to red and green upconversion emission in MnCl2:Yb3+ and Zn2SiO4:Yb3+; Mn2+, respectively. The photon upconversion (UC) emission is centered around 15,240cm−1 for MnCl2:Yb3+ and around 19,050cm−1 for Zn2SiO4:Yb3+; Mn2+ and is ascribed to the Mn2+4T1→6A1 transition in both compounds. The shift of the Mn2+ emission energy is due to the different coordination and ligand strength. Pulsed measurements indicate a sequence of ground-state absorption (GSA) and excited-state absorption (ESA) steps for the upconversion process. We conclude that the UC process in both compounds occurs by an exchange mechanism involving Yb3+ and Mn2+ ions. Zn2SiO4:Yb3+; Mn2+ is the first example of a Yb3+–Mn2+ upconversion system to show visible (VIS) by eye Mn2+ UC emission at room temperature.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
