Ni增强Er在富硅氮化硅薄膜中的光致发光

采用反应磁控溅射技术沉积了掺Er的富硅氮化硅(SRN:Er)薄膜和SRN:Er/Ni3个周期的超晶格,两种薄膜都在1100℃进行退火实验。SRN:Er薄膜的光致发光谱为一个峰位在665～750nm的发光带和一个峰位在1.54μm的发光带,前者来源于SRN薄膜中的纳米硅,后者为Er3+的特征发射。SRN:Er/Ni超晶格的光致发光谱上出现Er3+在520,550和850nm附近的精细结构,并且Er3+在1.54μm的发光有12倍的增强。光谱精细结构的出现证明Er3+的微观环境由于掺Ni而变得有序。与在SRN中相比,在这种有序环境中Er3+的光学活性有明显的增强。拉曼散射光谱测量证明在SRN:Er/Ni超晶格中纳米硅的数目比在SRN:Er薄膜中有一定的增加。因而,Er3+1.54μm发光12倍的增强是Er3+本身光学活性的增强和纳米硅数目的增加共同作用的结果。

Ni-Enhanced Photoluminescence of Er~(3+) Doped in Si-Rich Nitride

Er-doped Si-rich nitride (SRN∶Er) films and three-period superlattices of SRN∶Er /Ni were deposited by reactive magnetron sputtering technique and annealed at 1100℃. The photoluminescence spectra of SRN∶Er films show two emission bands, one centered at 665～750 nm and another peaked at 1.54 μm, where the 665～750 nm one is due to Si nanocrystals in SRN and the 1.54 μm one is characteristic for Er~(3+). The photoluminescence spectra of the superlattices exhibit fine structures of Er~(3+) light emission around 520, 550 and 850 nm and a 12-fold enhanced Er~(3+) light emission at 1.54 μm. The appearance of these fine structures indicates that the local environments around Er~(3+) become ordered and Er~(3+) is much more optically active in such ordered environments than in SRN∶Er films. Raman-scattering spectra measurements demonstrate an increase in the number of Si nanocrystals. Therefore, the 12-fold enhancement at 1.54 μm is a result of the enhancement in the Er~(3+) optical activation and the increase in the number of Si nanocrystals.