论文部分内容阅读
采用图形化蓝宝石衬底(PSS)技术可以降低GaN外延层材料位错密度,提高了发光二极管(LED)的内量子效率(IQE),同时使LED光析出率(LEE)提高。基于PSS技术可以制作高效GaN基高亮度LED。基于已公开发表文献对用于高效LED制作的PSS技术做了综述,介绍了PSS技术演化、PSS的制作方法与主要的图形结构、PSS上GaN外延层生长机制以及PSS对LED性能的影响。PSS结构对LED的IQE与LEE均有提高,但对二者哪个提高更为有效没有定论,最近的研究结果倾向于以为对LEE提高更为有效。PSS对LED的IQE与LEE提高的机制目前并不是非常清楚,对公开发表的PSS对LEE的提高机制提出了不同看法。不同PSS结构与尺寸对GaN质量以及LED性能的影响方面的研究目前还非常缺乏。
The use of a patterned sapphire substrate (PSS) reduces the dislocation density of the GaN epitaxial layer material and increases the internal quantum efficiency (IQE) of the light-emitting diode (LED) while increasing the LED light extraction rate (LEE). Based on PSS technology can produce efficient GaN-based high-brightness LED. Based on the published literature, the PSS technology for efficient LED fabrication is reviewed. The evolution of PSS technology, the fabrication method and main structure of PSS, the growth mechanism of GaN epitaxial layer on PSS and the influence of PSS on LED performance are introduced. PSS structure of the LED IQE and LEE are improved, but which of the two to improve more effective is not conclusive, the recent findings tend to think that more effective in improving the LEE. The mechanism by which PSS improves the IQE and LEE of LED is not very clear at present, and different opinions are put forward on the published mechanism of improving LEE by PSS. The research on the influence of different PSS structures and sizes on the quality of GaN and the LED performance is still lacking.