发光纳米硅/二氧化硅多层膜的特性与氢气氛退火的影响

利用等离子体增强化学气相沉积法制备了氢化非晶硅/二氧化硅多层膜，通过两步热退火的方法获得了尺寸可控的纳米硅/二氧化硅多层结构，晶粒尺寸约为4nm，在室温下观察到了较强的光致可见发光，其发光峰位于750nm.在此基础上，发现合适的氢气氛退火能有效地提高材料的发光强度.电子顺磁共振实验表明氢气氛退火有效地降低了纳米硅中的非辐射复合中心而导致发光效率的提高.

Characteristics of luminescent nc-Si/SiO2 multilayers and the influence of annealing in hydrogen

Plasma enhanced chemical vapor deposition (PECVD) was used to prepare a-Si:H/SiO₂ multilayers. Two-step thermal annealing was then used to transform them into nc-Si/SiO₂ multilayers. The size of formed nc-Si (about 4nm) can be controlled and room temperature visible photoluminescence was observed from the annealed samples with the peak located at 750nm. Moreover, we found that annealing in hydrogen can enhance the PL intensity of the materials. The electron paramagnetism resonance (EPR) suggested that annealing in hydrogen atmospheye effectively reduces the nonradiative recombination sites existing in the nc-Si and results in the enhancement of the luminescence efficiency.