Identification of a Blue Photoluminescent Composite Material from a Combinatorial Library

Abstract

A quaternary combinatorial masking strategy was used in conjunction with photolithography to generate compositionally diverse thin-film phosphor libraries containing 1024 different compositions on substrates 2.5 centimeters square. A parallel imaging system and scanning spectrophotometer were used to identify and characterize compositions in the library with interesting luminescent behavior. Optimal compositions were identified with the use of gradient libraries, in which the stoichiometry of a material was varied continuously. This process led to the identification of an efficient blue photoluminescent composite material, Gd₃Ga₅O₁₂/SiO₂. Experimental evidence suggests that luminescence in this material may arise from interfacial effects between SiO₂ and Gd₃Ga₅O₁₂.