Strong Absorption Enhancement in Si Nanorods

详细信息    查看全文

• 作者：Ilya Sychugov ; Fatemeh Sangghaleh ; Benjamin Bruhn ; Federico Pevere ; Jun-Wei Luo ; Alex Zunger ; Jan Linnros
• 刊名：Nano Letters
• 出版年：2016
• 出版时间：December 14, 2016
• 年：2016
• 卷：16
• 期：12
• 页码：7937-7941
• 全文大小：379K
• ISSN：1530-6992

文摘

We report two orders of magnitude stronger absorption in silicon nanorods relative to bulk in a wide energy range. The local field enhancement and dipole matrix element contributions were disentangled experimentally by single-dot absorption measurements on differently shaped particles as a function of excitation polarization and photon energy. Both factors substantially contribute to the observed effect as supported by simulations of the light-matter interaction and atomistic calculations of the transition matrix elements. The results indicate strong shape dependence of the quasidirect transitions in silicon nanocrystals, suggesting nanostructure shape engineering as an efficient tool for overcoming limitations of indirect band gap materials in optoelectronic applications, such as solar cells.