Abstracts 2001

Abstract of Publication No. 391

Pascal Gerner, Oliver S. Wenger, Rafael Valiente and Hans U. Güdel
Green and Red Light Emission by Upconversion from the near-IR in Yb3+ Doped CsMnBr3
Inorg. Chem. 40, 4534-4542 (2001)      Full Text (PDF)      DOI-Link     

Abstract: Direct near-IR excitation of Yb3+ 2F7/2 2F5/2 levels at 10126, 10138, and 10596cm1 in CsMnBr3:0.5%Yb3+ leads to three types of luminescence at cryogenic temperatures: near-IR Yb3+ emission and green and red upconverted luminescence. The green luminescence around 20000cm1 is identified as cooperative Yb3+ pair upconversion. The broad red upconversion luminescence band centered at 14700cm1 is ascribed to the 4T1g 6A1g transition of Mn2+. Pulsed measurements indicate a sequence of ground-state absorption and excited-state absorption steps for the red upconversion process. One- and two-color excitation experiments support this, and we conclude that the red upconversion occurs by an exchange mechanism involving Yb3+ and Mn2+. The Yb3+ 2F5/2 2F7/2 near-IR emission around 10000cm1 is also observed after Mn2+ excitation at 21838cm1. This is indicative of a Mn2+ 4T1g Yb3+ 2F5/2 relaxation process, which is a potential loss process for upconversion efficiency.

Last modified: 13.12.11 by Gabriela Frei