Abstracts 2005

Abstract of Publication No. 526

Sara García-Revilla, Pascal Gerner, Hans U. Güdel and Rafael Valiente
Yb3+-sensitized visible Ni2+ photon upconversion in codoped CsCdBr3 and CsMgBr3
Phys. Rev. B 72, 125111/1-9 (2005)      Full Text (PDF)      DOI-Link     

Abstract: Near-infrared excitation of Yb3+ 2F7/2 2F5/2 at 10600 cm–1 in the linear chain CsMBr3:Ni2+,Yb3+ (M=Cd,Mg) structure leads to green luminescence from Yb3+ pairs and red Ni2+ upconversion luminescence at cryogenic temperatures. The broad red upconversion luminescence is assigned to the 1T2g 3A2g transition of Ni2+. The upconversion excitation spectrum indicates that the active mechanism in these systems involves both Yb3+ and Ni2+ ions. Lifetime and power dependence data allow one to identify a ground-state-absorption (GSA) energy-transfer upconversion (ETU) as the underlying upconversion mechanism for the Yb3+-Ni2+ system in doubly doped CsCdBr3 and CsMgBr3. A less efficient single-ion GSA excited-state-absorption (ESA) process within Ni2+ is also observed in the title compounds. However, whereas the GSA/ESA process requires an excitation energy above 11200 cm–1, it is possible to sensitize the Ni2+ upconversion via Yb3+ excitation at energies around 10200 cm–1 and around 10600 cm–1 in CsCdBr3 and CsMgBr3. It is shown that only those Ni2+ ions neighboring to Yb3+ ions are relevant for the upconversion induced by Yb3+ excitation.

Last modified: 13.12.11 by Gabriela Frei