摘要
为提高发光亮度,本文详细分析了场致发光中的瓶颈过程。发现碰撞激发截面的五个特征:依赖入射电子方向,依赖入射电子能量,依赖发光中心寿命,依赖末态密度,存在不同阈值对不同激发态。并以ZnS:ErF_3的绿、红发光强度比为内标,在有源区外,设置预热层及加速层,选取合适材料,获得及证实了所得过热电子具有较一般结构中更高的平均能量,并对激发截面的某些特征作了实验论证。从实验上直接证明了离化倍增,并计算了它的系数,比文献中报导的都高。它同时显示了采用阴极射线发光材料,以获得彩色发光的可能性。
In this paper,we analysed the bottle-necks processes in electroluminescence in order to raise the brightness of its radiation.Five characteristics of impact excitation cross-sec- tion are discovered:dependence on the direction of impinging electrons(anisotropy), dependence on the energy of impinging electrons,dependence on the life-time of luminescent centers,dependence on the density if final states and the existence of thresh- old energy for each level.By using the ratio of green to red emission of ZnS.Er^(3+) as internal standard of electron energy,and setting up contiguous layers of preheating and accelerating electrons outside of light emitting layer as well as selecting the appropriate materials,we have obtained hot electrons with much higher average energy than that obtained in conventional method.The results proved then some of the theoretical predictions of impact excitation cross-section. We proved also experimentally the process of multiplication of carriers by impact ionization and calculated its value.It is shown that this value is higher than that given in literature.These results show at the same time the possibility of obtaining color luminescence by using the well-known cathodoluminescent phoshors.
出处
《天津理工学院学报》
1991年第1期10-19,共10页
Journal of Tianjin Institute of Technology
基金
本项目由国家自然科学基金委员会资助
关键词
场致发光
激发
碰撞
截面
impact excitation
thin film electroluminescence
anisotropy
multiplication
