Synthesis and Optical Characterisation of Barium Magnesium Aluminate Nanophosphors as Blue Light Emitting Source

Abstract

Extensive research has been carried out on the blue light emitting phosphors till date. The blue phosphor is an important and promising candidate in display and lighting technology. BaMgAl10O17:Eu2+ (BAM:Eu2+) is the commercially used blue phosphor. The present work studies the photoluminescence properties of BAM:Eu2+ nanophosphors prepared by solution combustion synthesis process. Activator concentration, phase purity, crystallinity and morphology are the governing factors for high luminescence efficiency for any phosphor. Based on these factors various techniques were used and studied to enhance the photoluminescence efficiency of the BAM:Eu2+ nanophosphors. The entire work in this thesis is presented in seven chapters. The outline of these seven chapters is given below. Chapter 1 discusses the fundamentals of photoluminescence giving an insight into the trivalent and divalent rare earth ions as luminescent centers. This chapter also covers some important topics explaining luminescence phenomenon in phosphors. Red, green and blue light emitting phosphors are discussed concisely. Applications of phosphors are given in brief. Importance of blue phosphors and a brief introduction to BaMgAl10O17 host material concludes the chapter. Chapter 2 summarizes current research in the field of phosohors. Earlier reported work of various researchers has been reviewed. Effect of various parameters on morphological and optical properties of BAM has been given. The chapter discusses BAM phosphors along with different synthesis routes, effect of co-doping, alkali ion incorporation, polymer addition, theoretical assessment and degradation mechanism. The last section of the chapter gives gaps in the study and the objectives for the work presented in the thesis. Chapter 3 gives the experimental details followed for the synthesis of the materials and different characterization techniques used during the course of present study.