不同密度银纳米粒子对氧化锌基发光二极管发光的增强

摘要

Localized surface plasmon resonance enhanced n-ZnO/i-ZnO/MgO/p-GaN heterostruc-ture light-emitting diodes ( LEDs) with different sliver nanoparticles ( Ag NPs) density were fabrica-ted using molecular-beam epitaxy technique. It is found that the introduction of Ag NPs with suitable density is favorable for the effective resonant coupling between excitons in ZnO and the localized sur-face plasmons of Ag NPs, and thereby significantly improves the electroluminescence ( EL) perform-ance of the device. Note that the enhancement ratio increases firstly with the Ag NPs density and then decreases, and the variation is believed to be resulted from balance between the enhancement caused by the resonant coupling between the excitons in ZnO and the localized surface plasmons of Ag NPs and the extinction of the emitted photons by the Ag NPs.%采用分子束外延法制备不同密度的银纳米粒子（ Ag NPs）修饰的局域表面等离子体共振增强n-ZnO/i-ZnO/MgO/p-GaN 异质结发光二极管（ LEDs）,并对其电学及光学性质进行表征。结果显示：LEDs中引入适当浓度的Ag NPs有利于Ag NPs局域表面等离子体激元与ZnO激子相耦合,可以显著提高器件的电致发光性能；随着Ag NPs浓度的增加,LEDs发光增强倍数先增大后减小,分析认为这是Ag NPs局域表面等离子体共振耦合增强过程和Ag NPs的消光过程两者之间相互博弈而导致的结果。