Optical properties of the photonic crystals based on nano-crystalline-Si-dispersed films as an optically active medium

纳米硅分散薄膜是一种新型发光材料，它是由纳米硅分散组成的氧化硅薄膜，具有高效的可见光致发光。在此之前，我们已经证明了利用垂直光学腔可以有效地缩窄纳米硅分散薄膜中的宽发光带宽。在本项目中，我们的目标是利用二维(2D)光子晶体来实现对纳米硅分散薄膜的光发射光谱的高阶控制。形成了晶格常数为400 nm和350 nm的三角形晶格。采用合适进气比的CF4-H2等离子体实现了纳米硅分散膜的各向异性刻蚀。结果表明，二维光子晶体结构充分抑制了出射光沿薄膜的传播。另一方面，二维光子晶体结构对发射光的光谱和强度的影响尚不清楚。

Nanocrystalline (nc-) Si-dispersed films, which are the silicon oxide thin films including nc-Si dispersively, are a new light-emitting material providing high efficiency visible photolminescence (PL). Previously, we have demonstrated that broad PL band width in the nc-Si-dispersed films can be narrowed effectively using a virtical optical cavity. In this project, we aimed to achieve a higher-order control of the light emission spectra of the nc-Si-dispersed films utilizing a two dimensional (2D) photonic crystal.The 2D photonic crystal structure was formed using an electron-beam lithography system. A triangular lattice with a lattice constant of 400 nm and 350 nm have been formed. The anisotropic etching of the nc-Si-dispersed films was achieved by using a CF_4-H_2 plasma of an appropriate feed gas ratio. It was confirmed that the propagation of emitted light along the layer was sufficiently suppressed by the 2D photonic crystal structure. On the other hand, the effect of the 2D photonic crystal structure on the spectra and intensity of the emmited light was not clear.