Yb³⁺-Er³⁺-Tm³⁺ co-doped nano-glass-ceramics tuneable up-conversion phosphor

¹ Dpto. Física Fundamental y Experimental, Electrónica y Sistemas, Universidad de La Laguna, 38206 La Laguna, Tenerife, Spain
² Chemistry Department, Katholieke Universiteit Leuven, Leuven, 3001 Belgium
³ Dpto. Física Básica, Universidad de La Laguna, 38206 La Laguna, Tenerife, Spain

Corresponding author: vrguez@ull.es

Received: 21 December 2007
Revised: 29 April 2008
Accepted: 13 May 2008
Published online: 19 July 2008

Abstract

Transparent Yb³⁺-Er³⁺-Tm³⁺ co-doped nano-glass-ceramics have been prepared, 32(SiO₂) 9(AlO_1.5) 31.5(CdF₂) 18.5(PbF₂) 5.5(ZnF₂): 3.5(Yb-Er-TmF₃) mol%, where the co-dopants partition mostly to the fluoride PbF₂-based nano-crystals. A comparative study of the up-conversion luminescence in nano-glass-ceramics and its precursor glass indicates that these materials can be used as blue/green/red tuneable up-conversion phosphor, in particular for white light generation. A ratio between blue, green and red emission bands of the Tm³⁺ and Er³⁺ can be widely varied with nano-ceramming of the precursor glass and with changing a pump power of luminescence. The change in the ratio between the blue, green and red emission bands is explained to be due to substantial lowering phonon energy and shortening of inter-dopant distances with nano-ceramming of the precursor glass and due to change in the ratio of 2- and 3-photon up-conversion processes with pump power.