光电技术第6章2.pptx

光源
热辐射光源
气体放电光源
固体发光光源
激光器
太阳
白炽灯、卤钨灯
黑体辐射器
***灯
荧光灯
钠灯
氙灯
金属卤化物灯
空心阴极灯
场致发光灯
发光二极管
气体激光器
固体激光器
染料激光器
半导体激光器
温度辐射
发光
光致发光
阴极射线发光
放射线发光
电致发光
注入式电发光
光谱功率分布图
~2 LED (Light emitting diode)
全彩色LED电子显示屏
三星LED光源DLP背投电视
两组高科技显示屏宽均为50米,高7﹒5米,采用点间距16毫米的全彩色LED像素,整屏分辨率3072x320点
远程同步控制,高清数字显示,其横向3072点像素是迄今为止世界上广场LED显示屏之最。
A light emitting diode(LED) is essentially a pn junction diode typically made from a direct bandgap semiconductor, for example GaAs, in which the electron hole pair (EHP) bination results in the emission of a photon.
1. Principles
The phenomenon of light emission from EHP bination as a result of minority carrier injection as in this case is called injection electroluminescence.(注入电致发光)
Because of the statistical nature of the bination process between electrons and holes, the emitted photons are in random directions; they result from spontaneous emission processes in contrast to stimulated emission.
Heterostructure LED
A junction between two differently doped semiconductors that are of the same material is called a homojunction.
A junction between two different different bandgap semiconductors is called a heterojunction.