The Effect of Annealing Temperature on the CL Properties of Sol-Gel Derived Y[sub 2]O[sub 3]:Re (Re=Eu[sup 3+],Tb[sup 3+],Tm[sup 3+]) Phosphors

Red, green, and blue-emitting Li-doped ( , , or ) film phosphors were coated on sapphire substrates using a sol-gel technique in which yttrium nitrate, metal nitrate ( , , or ), lithium carbonate, and citric acid were used as the precursor materials. The effect of annealing temperature on thin films and thick films on sapphire substrates was studied with respect to the structural and cathodoluminescence (CL) properties of the film phosphors. The structural and optical trends observed as a function of annealing temperature differed between the thin and thick films. The ( , , or ) red, green, and blue thick films annealed at showed the highest volume and crystallinity of the phase and CL intensity of Li-doped red, green, and blue phosphors. These results for thick-film phosphors are discussed on the basis of the optical properties, such as the CL spectrum, color coordinates, brightness, and longevity.