硅-二氧化硅超晶格——探索硅基发光材料的一条新途径

Si/SiO 2 SUPERLATTICES ——A NEW ROUTE FOR Si BASED LIGHT EMITTING MATERIALS

理论上认为，由于Ｓｉ／ＳｉＯ２超晶格中硅层（阱层）的电子和空穴都受到极强的量子限制效应，硅层能带有可能从体硅的间接带隙转变为直接带隙，从而发光效率大大提高．实验上，在非晶Ｓｉ／ＳｉＯ２超晶格中观察到在可见光波段的室温光致发光和明显的量子限制效应现象．晶体Ｓｉ／ＳｉＯ２超晶格研究也取得了初步的结果．

Because both electrons and holes of Si (well) layers in Si/SiO 2 superlattices are subjected strongly to quantum confinement effects, it is possible for the energy gap in the Si layers to change from indirect to pseudodirect,thus dramatically increasing luminescence efficiency.For a Si/SiO 2 superlattices room temperature photoluminescence was observed at wavelengths across the visible range for an a Si layer thickness of 1_3nm.The fitted peak emission energy is in accordance with the quantum confinement effect. Research on crystal Si/SiO 2 superlattices has made substantial progress.