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

纳米硅分散薄膜是指纳米硅分散在氧化硅薄膜中，是一种新型的可见光致发光材料。以前，我们已经证明，广泛的PL带宽的nc-Si分散膜可以有效地缩小使用的虚拟光学腔。在本计画中，我们的目标是利用二维光子晶体来实现奈米矽分散薄膜发光光谱的高阶控制，二维光子晶体结构是利用电子束微影系统来形成。已经形成了具有400 nm和350 nm的晶格常数的三角形晶格。采用合适的CF_4-H_2等离子体对nc-Si分散膜进行了各向异性刻蚀。确认了发射光沿着该层的传播被2D光子晶体结构充分抑制。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.