Upconversion emission in (Ln,Yb):KLu(WO4)2 nanocrystals for white light generation

Abstract

Optical active lanthanides ions in double tungstates exhibit high emission cross section with low concentration quenching. Production of double tungstates nanocrystals doped with lanthanide ions is suitable for applications in white light emitters if high quantum yield is reached. In this work lanthanide doped (Ln:Yb):KLu(WO4)2 nanocrystals (Ln Er, Tm, Ho) upconversion emission properties have been study after 980 nm diode laser excitation at 14-334 W/cm2. From CIE chromaticity theory a possible mixture weight ratio to obtain a white light emitter powder was predicted. Luminescence under 980 nm of the (Ln:Yb):KLu(WO4)2 nanocrystals was study and decay times under 460 nm was measured. Reduction of the upconversion quantum yield was observed in the case of physical mixture of nanocrystals. © Published under licence by IOP Publishing Ltd.