title: Strong Absorption Enhancement in Si Nanorods.
abstract: 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.
authors.affiliation: Materials and Nano Physics Department, KTH - Royal Institute of Technology , Kista, Stockholm, 16440, Sweden.
authors.forename: Ilya
authors.initials: I
authors.lastname: Sychugov
authors.affiliation: Materials and Nano Physics Department, KTH - Royal Institute of Technology , Kista, Stockholm, 16440, Sweden.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Sangghaleh
authors.affiliation: Materials and Nano Physics Department, KTH - Royal Institute of Technology , Kista, Stockholm, 16440, Sweden.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Bruhn
authors.affiliation: Materials and Nano Physics Department, KTH - Royal Institute of Technology , Kista, Stockholm, 16440, Sweden.
authors.forename: Federico
authors.initials: F
authors.lastname: Pevere
authors.affiliation: State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences , P.O. Box 912, Beijing 100083, China.
authors.forename: Jun-Wei
authors.initials: JW
authors.lastname: Luo
authors.affiliation: Renewable and Sustainable Energy Institute, University of Colorado , Boulder, Colorado 80309, United States.
authors.forename: Alex
authors.initials: A
authors.lastname: Zunger
authors.affiliation: Materials and Nano Physics Department, KTH - Royal Institute of Technology , Kista, Stockholm, 16440, Sweden.
authors.forename: Jan
authors.initials: J
authors.lastname: Linnros
keywords: Absorption; atomistic theory; nanocrystals; nanorods; silicon