Structural Stokes and anti Stokes luminescence properties of trivalent lanthanide ions doped A3Ga5O12 A equal to Gd Y and Lu nanocrystals

Abstract

newline The thesis entitled Structural, Stokes and anti-Stokes luminescence properties of newlinetrivalent lanthanide ions -doped A3Ga5O12 (A = Gd, Y and Lu) nanocrystals presents an newlineinvestigation on structural, morphological, vibrational, and luminescence properties of Nd3+- newlineYb3+, Er3+-Yb3+, Tm3+-Yb3+ and Ho3+-doped A3Ga5O12 (AGG, A = Gd, Y and Lu) newlinenanocrystals. The Ln3+ ion doped inorganic materials are important class of luminescent newlinematerials for applications in solid state lasers, light converters, temperature and pressure newlinesensors, phosphors for solid state lighting, display devices, bio-imaging, photovoltaic, newlinephotocatalysis, etc. The development of nanocrystalline luminescent materials for specific newlineapplication requires the detailed investigations on structural, morphological, vibrational, and newlineluminescence properties. In this direction, rigorous search for low phonon energy host with newlinehigh stability and suitable Ln3+ dopants with optimized concentration are highly essential to newlineachieve efficient luminescence. The luminescence of nanocrystalline materials mainly newlinedepends on particle size, morphology, doping concentration, crystallinity and phonon energy. newlineThe single crystals (bulk) doped with Ln3+ ions are well known, but there are several newlinelimitations such as time-consuming and the specialized sophisticated equipment for their newlineproduction. The solid state reaction method is simpler to produce powders with micrometer newlinesize by pulverization with shortcomings of formation of a surface dead layer, which provides newlinenon-radiative routes thereby lowering the luminescence efficiency. The facile techniques to newlinesynthesize the crystals directly in the nanometer regime have eliminated the need for such newlinepractices and have inspired a wealth of new possibilities. Hence, it stimulates an interest to newlinesynthesize Nd3+-Yb3+, Er3+-Yb3+, Tm3+-Yb3+, and Ho3+ ions in AGG nanocrystals by low newlinecost, environmentally benign method and characterize for their structural, morphological, newlinevibrational, and luminescence properties