摘要
We fabricate a-Si/a-SiN_(z) superlattices and a one-dimensional amorphous silicon nitride photonic crystalmicrocavity by plasma enhancement chemical vapor deposition(PECVD).To improve the light-emitting efficiency of the nc-Si/a-SiN_(z)superlattices,which are made from a-Si/a-SiN_(z)superlattices by laser annealing,an nc-Si quantum dot array is inserted into the photonic crystal microcavity.Raman spectroscopy and transmission electron microscopy analysis show that nc-Si with a size of 4nm,which is close to the designed thickness of the a-Si sublayers,is formed in the a-Si sublayers.Owing to microcavity effects,the PL peak of the nc-Si/a-SiN_(z)superlattices embedded in the microcavity is strongly narrowed,and the intensity of the PL is enhanced by two orders of magnitude with respect to the emission of A/2-thick nc-Si/a-SiN_(z)superlattices.Light emission at a cavity-resonant frequency from the nc-Si/a-SiN_(z)superlattices is enhanced while other frequencies are forbidden.This leads to the narrowing of the PL spectrum and enhancement of the intensity.
研究了一维光子晶体微腔结构对nc-Si/a-SiN_(z)超晶格发射的调制.一维光子晶体微腔采用两种具有不同折射率的非化学组分非晶氮化硅的周期调制结构,腔中嵌入采用激光晶化方法制备的硅量子点阵列,从Raman谱和透射电子显微镜分析得到其尺寸约为3~4 nm.从光致发光谱上观察到明显的选模作用、明显变窄的发光峰以及约两个量级的发光强度的增强.微腔对硅量子点阵列发光的调制主要表现在两个方面:共振模式的增强和非共振模式的抑制.硅量子点中位于腔共振模式的辐射跃迁被增强,非共振模式的辐射跃迁被抑制,因此位于腔共振频率处的跃迁通道成为硅量子点中唯一的辐射跃迁通道,导致光致发光谱的窄化和强度的增强.因此,在提高硅材料发光效率方面,光子晶体微腔具有非常大的应用前景.
基金
国家自然科学基金(批准号:10174035,90301009,10374049)
江苏省自然科学基金(批准号:BK2002407)
国家重点基础研究发展规划(批准号:2001CB610503)资助项目
