Abstracts 2004

Abstract of Publication No. 489

Pascal Gerner, Cyril Fuhrer, Christine Reinhard and Hans U. Güdel
Near-infrared to visible photon upconversion in Mn2+ and Yb3+ containing materials
J. Alloys Comp. 380, 39-44 (2004)      Full Text (PDF)      DOI-Link     

Abstract: Near-infrared (NIR) laser excitation into the Yb3+ 2F7/2 2F5/2 absorption transition around 10,200 cm−1 at 12 K leads to red and green upconversion emission in MnCl2:Yb3+ and Zn2SiO4:Yb3+; Mn2+, respectively. The photon upconversion (UC) emission is centered around 15,240 cm−1 for MnCl2:Yb3+ and around 19,050 cm−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.

Last modified: 13.12.11 by Gabriela Frei