The Study Of Luminescence Conversion White LEDs

It has been 10 years since the first white LED in the world was made in 1996. Comparing to fluorescent lamp and incandescent lamp, WLED is energy saving, high brightness, long-lifetime, none-radiation and doesn't contaminate the environment. More and more attentions are put to this novel region. WLED is believed to be the fourth generation of lamp-house after incandescent lamp, fluorescent lamp and discharge light and it is the future of illumination.According to luminescent material used, there are two kinds of WLED called i norganic and organic WLED. The study of making inorganic and organic WLED by the theory of Luminescence Conversion is introduced in this thesis.The technique of making luminescent material YAG:Ce 3+ is introduced and the factors that have effects to YAG:Ce3+ are investigated. YAG:Ce3+ is made under high temperature. The experiments of coating of YAG:Ce3+by lanthanum oxide and alumina are made and at the same time the coating's effects is studied by comparing the WLEDs used coating luminescent material with the WLEDs used normal material. Some productions of inorganic WLEDs are made, the properties of WLEDs, fluorescent lamp and incandescent lamp are studied.The weight ratio of riboflavin and anthrone, the weight of dispersing system LDPE and the heating time is studied during making the organic luminescent films. The possibility of achieving organic WLED using ax — 17 and zq — 13 is investigated. According to the theory of linear system, a new way of calculating the efficiency of fluorescence resonance energy transfer is investigated and it is proved by experiments.