Surface-specific visible light luminescence from composite metal oxide nanocrystals
Low-coordinated surface elements on metal oxide nanoparticles represent the basis for a new concept of luminescent nanoparticles made of abundant, non-toxic, and thermally stable materials. This combined experimental and theoretical study describes the generation and stability of Ba-doped MgO nanoparticle surfaces and their optical absorption and luminescence dependence on Ba loading. It is demonstrated that the vapor phase growth process employed here represents a particularly robust synthesis approach for particle powders with reproducibly adjustable photoluminescence emission properties in the range between blue and yellow light. Moreover, this in-depth characterization also provides an understanding of the electronic and optical characteristics of this nanoparticulate material with a so far unnoticed potential for solid-state light applications that are based on down conversion of UV light.
1. ::: ::: Formation of chemiluminescence emitters during the liquid-phase oxidation of olefins by molecular oxygen can proceed through peroxide radical disproportionation or through the breakdown of intermediate molecular oxidation products. ::: ::: ::: ::: ::: 2. ::: ::: A study of the kinetics of these processes has shown that the second of these two possibilities is realized through dioxetanes and polymeric peroxides formed by chain reactions in the oxidation process.