Luminescence and Conductivity Studies of doped Nano Lanthanum Silicate

Abstract

newline Nanostructured materials are those materials whose sizes are of the order of few newlinenanometers (1-100 nm). Currently, nanomaterials find wide applications in various newlinefields since, they exhibit some special properties. Among these nano materials newlineLanthanum silicate (La10Si6O27) finds lot of interest due to its unique properties like newlinelarge band gap (~ 5.5 eV), high surface area, high refractive index, dielectric newlinepermittivity, high oxygen ion conductivity, remarkable photoconductivity and better newlinehost material for luminescence. Due to these properties they find applications in newlineluminescence, gas sensor technology, optical coatings, varistor solid oxide fuel cells, newlinehigh temperature superconductors, catalysts, ceramic glass manufacturing etc. newlineRare-earth (RE) ions activated visible emissive phosphors play a prominent role in newlinedisplay devices. RE ions are extensively used as luminescent centres in phosphors newlineowing to their f-f transitions. La10Si6O27 doped with RE3+ ions are promising newlinematerials for color light emission. newlineRegarding luminescence efficiency of La10Si6O27, it can be altered by newlinechanging their compositions. Great improvements in luminescence efficiency of newlinephosphors were viii observed by doping with even very small quantities of newlinedopants/co-dopants. Currently, the research on efficient and inexpensive newlinenanophosphors is a challenging problem for new luminescent materials. Use of those newlinephosphor materials in light emitting diode (LEDs) was a major step in solid state newlinelighting technology. However, white light emitting diodes (WLEDs) are consider to newlinebe the next generation lighting system because of their excellent properties like high newlineluminous efficiency, low power consumption, environmentally friendly features newline(nontoxic), reliability and long life. newline