Chemical functionalization of silicene: spontaneous structural transition and exotic electronic properties.
Chemical functionalization of silicene: spontaneous structural transition and exotic electronic properties.
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DOI：
10.1103/physrevlett.111.145502
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发表时间：
2013-10
影响因子：
8.6
通讯作者：
Bing Huang;Hongjun Xiang;S. Wei
中科院分区：
文献类型：
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作者：
Bing Huang;Hongjun Xiang;S. Wei
新发现的硅烯在各种光电应用中的应用在很大程度上取决于通过化学官能化控制其电子性质的可能性。为了研究这种可能性，我们系统地研究了化学官能化的硅烯的结构和电子性质，采用第一性原理计算结合集团膨胀的方法。有趣的是，我们发现，化学功能化的外延硅烯通常伴随着一个自发的结构转变，这源于硅的sp（3）杂化的偏好。为了实现带隙连续可调，提出了在~900 K下对自支撑硅烯进行化学功能化.最后，我们预测亚稳态硅烯也可以作为一种重要的主体材料，通过替代掺杂制备新型功能材料。例如，发现的有序Si（8）P（4）可能是薄膜太阳能电池吸收体的强有力候选者。
The use of newly discovered silicene for various optoelectronic applications depends largely on the possibility of controlling its electronic properties by chemical functionalization. To investigate this possibility, we systemically study the structural and electronic properties of chemically functionalized silicene by employing first-principles calculations combined with the cluster expansion approach. Interestingly, we find that chemically functionalized epitaxial silicene is generally accompanied by a spontaneous structural transition, which originates from the preference of sp(3) hybridization of silicon. To realized continuously tunable band gaps, chemical functionalization of freestanding silicene at ~900 K is proposed. Finally, we predict that metastable silicene can also be used as an important host material to produce novel functional materials via substitutional doping. For example, the discovered ordered Si(8)P(4) could be a strong candidate for thin-film solar cell absorbers beyond bulk Si.