Research Progress In Rare Earth Luminescent Materials

In this paper we will synthetically analyse and conclude the study background, actuality, progress and learning opinion of rare earth luminescent materials, discuss the synthesis and application study of rare earth luminescent materials generally, deeply and systematically, and introduce the new development, trend, level, principle and technology. Base on these, the luminescence principle and formation nature of the luminescent material were described, and the application and development prospect of were discussed and look forward to.This paper summarized several of rare earth luminescent materials synthetic methods used presently at home and abroad. The synthetic methods included high temperature solid method, sol-gel process, combustion synthesis, hydrothermal synthesis, microwave radiation method, micro-emulsion method and so on. By compared with the advantages and shortcomings of every method, the conclusion we obtained was high temperature solid method was best. The synthetic methods of rare earth luminescent materials were prospected. The existing commercial processes all adopt high temperature solid method, but the defects such as high reaction temperature, long time, high energy loss are difficultly overcame. The sol-gel process, chemical precipitation method, hydrothermal synthesis all possess some defects: reaction period is long, operation process is complex, realization of industrialization is not easy. Microwave radiation method had preferable foreground and applied worth, but the biggest obstacle of its development was there was a lack of the microwave furnace that was fit for the large industrialization production, combustion synthesis was a kind of promising method that rare earth luminescent materials were synthesized simply, quickly, efficiently at lower temperature by. Though the time that combustion synthesis was applied to the field of luminescent materials synthesis was short, it has put up the good application prospect. By experimental investigation, we thought combustion synthesis was the most promising technology that instead of high temperature solid method and make the industrialization come true. Micro-emulsion method and sol-gel process are relatively perfect methods for the preparation of rare earth luminescent materials with nanometer size, because the sizes of the materials were prepared by these methods could be nanometer level and the particles were uniform. Rare earth with special morphology such as nano-sphere, nano-rods and nano-tubes could be prepared by the control of the reactive conditions and the addition of certain adjuvant.Nearly, the development of rare earth luminescent materials'application was very rapid, rare earth luminescent materials include photoluminescence (excitation by UV-light or visible light), cathode luminescence (excitation by electron beam), X-ray luminescence (excitation by X-ray) and electroluminescence (excitation by electric field) materials. Compared with non-rare earth fluorescent materials, the performances of rare earth fluorescent materials such as luminous efficiency and light color are better. Rare earth luminescent materials have become the main materials in information display, light engineering and optical communication et al because the rare earth ion has the special structure of its 4f and 4f5d energy level and charge transition state. Rare earth is the important compose of a good many functional materials such as luminescence, magnetic and superconductor materials etc. The particular properties such as electronics and optics owing to the electron energy level transition among 4f electrons of rare earth ions were full of foreground combined with a good many characters of nano-materials were different with bulk materials, so rare-earths doped luminescence materials have attracted great attention since their extensive applications in the fields such as information display, optoelectronic devices and laser technology. The characters of rare earth such as luminescence, magnetic, superconductor and so on were nearly relation with composes of the materials. So rare earth doped rare earth nanometer luminescent materials synchronously possessed the character of surface and quanta size effect synchronously were very promising functional material.