The Establishment And Preliminary Application Of The Electroluminescent Decay Measurement System

Electroluminescence technology has a great significance for lighting and display applications, and has become a hot field in luminescence. Meanwhile, luminescence decay is an important process of luminescence. It is important to measure lifetime for study of luminous mechanism. Therefore, research on electroluminescence decay process and measurement for electroluminescent lifetime, are both important to solve scientific problems on electroluminescence and luminescence decay. This paper mainly summarizes the disadvantages of traditional research on luminescence decay. To solve these problems, we established an electroluminescence decay measurement system, and accomplished the preliminary application of this system. This paper consists of five chapters. The first chapter mainly introduces the development of electroluminescence technology and luminescence decay research. The second chapter introduces the basic theory on electroluminescence. The third chapter focuses on the disadvantages of traditional research on luminescence decay, and built an electroluminescence decay measurement system which consists of theory, method and equipment. The fourth chapter aims at the measurement and research on the lifetime by using this system, and the last chapter is the conclusion.In this paper we summarized three disadvantages on the concept and the method in traditional research.1) two different concepts between luminescence decay and excited states, and the nature of light are not distinguished.2) The rule of luminescence decay is deduced based on the law of excited states, and there are no experimental supports for the boundary conditions assumption.3) The equipment for measuring lifetime is expensive and limited. Moreover, the traditional research ignored the external environment impact on lifetime.Based on these three problems, we established an electroluminescence decay measurement system which consists of concept, theory, method and equipment, and successfully measured the lifetime of the LEDs.(1) We rigorously defined the lifetime is the whole time when luminescence intensity drops to zero, neither the reduction in the number of excited states, nor the time when luminescence intensity drops to 1/Ï„.(2) Based on the theory on transformation of energy, we use periodic luminescence method, and pulse interval time as a time scale to measure the lifetime alternately. The principle and method based on the experiment are understandable and reliable as an innovation.(3) Based on these concepts and principles, we built an electroluminescence decay measurement system, and successfully measured the lifetime of the LEDs. Finally, we found the positive correlation between initial luminescence intensity and its lifetime, and proved that lifetime is not only related with the luminescent material, but also affected by the external environment.