Enhancement of photoluminescence of Ge/GeO2 core/shell nanoparticlesC. L. Yuan1 and P. S. Lee2
1 Department of Physics, Jiangxi Normal University - Nanchang 330022, Jiangxi, PRC
2 School of Materials Science and Engineering, Nanyang Technological University - Singapore 639798
received 20 April 2008; accepted in final form 30 June 2008; published August 2008
published online 7 August 2008
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.
78.40.Fy - Semiconductors.
78.67.Bf - Nanocrystals and nanoparticles.
78.55.-m - Photoluminescence, properties and materials.
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