发光衰减是发光的重要过程,测量发光寿命对研究发光机理十分重要,但传统研究在概念和方法上存在两个差错:(1)概念上认为衰减等同于激发态数目的减少,而忽视了衰减是发光强度的下降,两者是不同的概念;(2)方法上基于激发态规律推导,假设的边界条件不符合实际,没有实验的支持。同时,传统方法对设备的要求很高,且只限于光致发光。为了纠正差错,降低成本,搭建了一套全新的电致发光衰减测量系统,可用于所有可以周期激发的发光类型。从能量转换原理出发,采用周期激发,用脉冲间隔时间作为时间尺度来度量发光衰减持续的时间,通过脉冲间隔时间与发光寿命的对比,相应地发光强度有不同的变化,根据该现象简便地测量出发光寿命。基于该原理搭建的发光衰减测量系统,实验结果表明了发光强度随着激发频率,先保持不变然后逐渐下降,通过测量下折点即能够推算出发光衰减寿命,而且还发现发光衰减寿命与初始发光强度呈正相关的关系。认为发光寿命是发光强度的变化,是区别于传统研究以激发态数目为研究对象的一大创新,同时通过实验证明了发光寿命与初始亮度相关,也拓展了对发光寿命的新认识。
Luminescence decay is an important process of luminescence.It is important to measure the lifetime for the study of luminous mechanism.But there are two flaws in the traditional research on the concepts and methods:firstly in terms of the concepts,luminescence decay is considered as the reduction in the number of the excited states and ignored as the decline of the luminescence intensity,so they are different concepts.Secondly the methods are based on the change rule of the excited states and the boundary conditions without the support of the experiments do not conform to the reality.The traditional method is demanding as to the equipment and photoluminescence is necessary.In order to correct these two flaws and reduce the cost,a new electroluminescence decay measurement system is set up,which could be used for all periodic luminescence.Based on the principle of energy conversion,we use periodic luminescence method,and pulse interval time as a time scale to measure the lifetime easily.The luminescence intensity shows different rules through the comparison between the pulse interval time and the lifetime.A new luminescence measurement system is proposed based on this theory.The experimental result shows that the luminescence intensity keeps invariant and then gradually decline with the increase of excited frequency.We successfully measure the lifetime by measuring the inflexion point and also found a positive correlation between initial luminescence intensity and lifetime.We believe that lifetime is the change of the luminescence intensity.This is a great innovation different from the tradition research on the number of the excited states.At the same time,through the experiment it is proved that the lifetime is related to the initial intensity and increase the understanding of the lifetime.