Luminescent Nanocrystalline Metal Oxides

Luminescent metal oxides have drawn significant attention of the research community owing to their wide range of applications in the field of solid-state lighting, displays, gas sensors, and biomedical etc. The basic concepts of luminescence, types of luminescence, up-conversion, down-conversion and persistent luminescence mechanisms, role of metal oxide nanoparticles in luminescence, synthesis of size and shape controlled luminescent metal oxides nanoparticles (LMONPs) by different chemical methods and their characterization are briefly described in this chapter. The highly efficient and long-life energy saving light emitting diodes to overcome lighting crisis, mesoporous structure and their nanocomposites with organic and inorganic compounds provides better gas sensing activity and biocompatibility of magnetic/non-magnetic luminescent metal oxide nanoparticles encourage their usage in biomedical applications are also concisely discussed. The future challenges in this field are also cited along with proposed solutions to check the toxicity of nanoparticles and standard quality documentation for the global acceptance of synthesized LMNOPs size, shape, and morphology by using a particular method, precursors and solvents used, synthesis parameters for the particular device application.