Luminescent properties in the visible of Er3+/Yb3+ activated composite materials

In this work we present the results of our research on luminescent properties in the visible spectral rangeof two different composite materials – based on polymer (PMMA) and glass (B 2 O 3 –BaO–K 2 O) hosts dopedwith Er 3+ +Yb 3+ :Y 2 O 3 nanocrystallites. The luminescent properties of these two composites were carefullystudied on the basis of excitation and emission characteristics complemented by fluorescence dynamicsprofiles. The specific attention was given to the main deactivation mechanisms and up-conversionphenomena as well as analysis of the influence of host’s type on the optical properties of erbium ions. 2014 Elsevier B.V. All rights reserved. 1. IntroductionComposite materials, which are a combination of two phaseswith different optical and mechanical properties – for example, aglass or polymer matrix with embedded active nanocrystallites –may potentially enable designing and development the entirelynew class of light sources, combining advantages of small size,low cost and improved optical and mechanical properties. Thespecific nature of composite media allows obtaining the resultantfeatures non-observable in classical materials, like e.g. efficientemission (and lasing) in the short-wavelength spectral range inhigh-phonon oxide glasses or polymers. This, in turn, significantlyextends the area of possible applications in integrated optoelec-tronics, imaging systems, sensor networks, etc.The idea of the optical composite material is not new – the firstvitroceramic composites (based on glasses doped with crystallinephase) were developed in the late sixties by G.H. Beall and D.A.Duke in the Corning Glass Research & Development Laboratories[1]. The first reports about two-phase optically active materialsfor laser applications are dated back to the beginning of the 70s[2,3], and the first publications on the short-wavelength emissionin vitroceramic materials appeared in 1975 [4]. It should be noted,however, that despite many years of research, light sources basedon vitroceramic materials never have been applied commercially,which partly results from a complex and expensive technology oftheir manufacturing.Polymer materials are manufactured in a much simpler andlow-cost processes, therefore they have been tested with respectof luminescent and lasing properties from the very beginning ofthe development of laser technology. The first reports of researchon active nanocrystallites doped with rare earth ions dispersed inliquid polymer matrix can be found in R.S. Meltzer works of 2001[5,6]. The work of J. W. Stouwdam team results in constructionof the planar amplifier based on PMMA doped with Nd