EPL, 83 (2008) 47010
DOI: 10.1209/0295-5075/83/47010

Enhancement of photoluminescence of Ge/GeO₂ core/shell nanoparticles

C. L. Yuan¹ and P. S. Lee<sup>2

1</sup>  Department of Physics, Jiangxi Normal University - Nanchang 330022, Jiangxi, PRC
²  School of Materials Science and Engineering, Nanyang Technological University - Singapore 639798

clyuan@jxnu.edu.cn

received 20 April 2008; accepted in final form 30 June 2008; published August 2008
published online 7 August 2008

Abstract
Ge/GeO₂ core/shell nanoparticles embedded in an Al₂O₃ gate dielectrics matrix were fabricated. The core/shell nanoparticles consist of a single-crystal Ge core and a tiny Ge/GeO₂ nanocrystallites shell. The high percentage of defects located at the shell surfaces and the grain boundaries between the Ge/GeO₂nanocrystals or disorderly arranged areas in the GeO₂shell induce a significant phonon localization effect, which leads to enhanced radiative recombination and thus it enhances the photoluminescence intensity. We believe that the findings presented here provide physical insight and offer useful guidelines to controllably modify the optical properties of indirect semiconductors through defect engineering.

PACS
78.40.Fy - Semiconductors.
78.67.Bf - Nanocrystals and nanoparticles.
78.55.-m - Photoluminescence, properties and materials.

© EPLA 2008