Silicon and silicon oxide core-shell nanoparticles: Structural and photoluminescence characteristics

Ray, Mallar and Sarkar, S and Bandyopadhyay, N R and Hossain, S M and Pramanick, A K (2009) Silicon and silicon oxide core-shell nanoparticles: Structural and photoluminescence characteristics. Journal of Applied Physics, 105 (7). 074301.

Restricted to NML users only. Others may use ->



We report the synthesis of spherical core-shell structures of silicon and silicon oxide by a novel route of forced external oxidation of ball milled silicon. Structural investigations reveal the formation of a crystalline silicon core surrounded by an amorphous oxide shell, with core and shell dimensions varying approximately between 4-10 and 55-170 nm, respectively. The observations suggest partial amorphization of crystalline silicon, invasive oxygen induced passivation of dangling bonds, and formation of different types of defects in the nanocrystalline silicon/silicon oxide core-shell structure, particularly at the interfaces. No detectable photoluminescence (PL) is obtained from the as-milled silicon, but the oxidized core-shell structures exhibit strong room temperature PL, detectable with unaided eye. The peak energy of the PL spectra blueshifts with an increase in excitation energy, with the peak positions varying from 2.24 to 2.48 eV under external excitation ranging from 2.41 to 3.5 eV. The observed PL characteristics are explained in terms of dominant electronic transitions between the localized defect states and quantum confinement induced widened band states. c 2009 American Institute of Physics. [DOI: 10.1063/1.3100045]

Item Type:Article
Official URL/DOI:DOI: 10.1063/1.3100045
Uncontrolled Keywords:Atomic-Force Microscopy; Porous Silicon; Nanocrystalline Silicon; Si Nanocrystals; Electronic-Structure; Quantum Dots; Luminescence; Films; Electroluminescence; Nanowires
Divisions:Material Science and Technology
ID Code:3240
Deposited By:Sahu A K
Deposited On:11 Jul 2011 15:15
Last Modified:08 Feb 2012 16:33
Related URLs:

Repository Staff Only: item control page