nc-Ge/SiN_x多层膜的光致发光特性

Photoluminescence of Nanocrystalline-Ge/SiN_x Multilayers

通过将a-Ge∶H/a-SiN_x多层膜进行氧化,制备了nc-Ge/SiN_x多层膜。观察到了室温下的强烈可见光发射,发光波长为500nm。通过分析,排除了与量子限制效应有关的光发射机制,也排除了与Si和N相关的缺陷产生的复合机制,认为该发光源于氧化后的a-SiN_x介质层中带尾态之间的辐射复合,最有效的激发能量约为介质层的带隙。

Nanocrystalline-Ge（nc-Ge）/amorphous-SiNx（a-SiNx） multilayers（ MLs） were fabricated by oxidizing hydrogenated amorphous-Ge（a-Ge∶ H）/a-SiNx multilayers. Its strong photoluminescence（PL）,peak at 500 nm,was observed at room temperature. Then,the mechanism of PL was studied,which indicated that the light emission was irrelevant to quantum confinement effect. The recombination of defects related to Si or N was also excluded. It is believed the PL of nc-Ge/SiNx MLs is originated from the radiative recombination of tail states of oxidized a-SiNx matrix,and the most effective excitation energy is close to the optical band gap of matrix.