Influence of SiO2 matrix on electronic and optical properties of Si nanocrystals
Influence of SiO2 matrix on electronic and optical properties of Si nanocrystals
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DOI：
10.1088/0957-4484/20/13/135702
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发表时间：
2009-04-01
期刊：
影响因子：
3.5
通讯作者：
Kroll, P.
中科院分区：
文献类型：
--
作者：
Seino, K.;Bechstedt, F.;Kroll, P.
基于从头算密度泛函理论，我们研究了镶嵌在非晶SiO2网络中的Si纳米晶体的电子性质和光学响应。研究了直径为0.8 ~ 1.6nm的准球形点。嵌入在SiO2中的Si纳米晶体的结果进行了比较与氢化的Si纳米晶体的相同大小的相应结果。计算结果表明了界面对电子性质的影响。结果与最近的实验数据进行了比较，并进行了详细讨论。作为引人注目的特征，由于氧化物的存在，预计间隙及其直径变化会大幅减少。电子限制主要影响吸收边，而在较高的光子能量，只有宽峰几乎固定的位置发生。
Based on ab initio density functional theory we present electronic properties and the optical response for Si nanocrystals embedded in amorphous SiO2 networks. Quasi-spherical dots with diameters from 0.8 to 1.6 nm are investigated. The results for Si nanocrystals embedded in SiO2 are compared with corresponding results for hydrogenated Si nanocrystals of the same size. The calculations show the influence of the interface between nanocrystal and matrix on the electronic properties. The results are compared with recent experimental data and discussed in detail. As striking features, strong reductions of the gaps and their diameter variation are predicted due to the oxide presence. Electronic confinement mainly influences the absorption edge while at higher photon energies only broad peaks at almost fixed positions occur.