Effect of graphene on photoluminescence properties of graphene/GeSi quantum dot hybrid structures

Journal Article · Mon Jul 14 04:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4889890· OSTI ID:22311061

Chen, Y. L.; Ma, Y. J.; Wang, W. Q.; Ding, K.; Wu, Q.; Fan, Y. L.; Yang, X. J.; Zhong, Z. Y.; Chen, D. D.; Xu, F. ^[1]

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1. SHU-SolarE R and D Lab, Department of Physics, College of Science, Shanghai University, Shanghai 200444 (China)

Graphene has been discovered to have two effects on the photoluminescence (PL) properties of graphene/GeSi quantum dot (QD) hybrid structures, which were formed by covering monolayer graphene sheet on the multilayer ordered GeSi QDs sample surfaces. At the excitation of 488 nm laser line, the hybrid structure had a reduced PL intensity, while at the excitation of 325 nm, it had an enhanced PL intensity. The attenuation in PL intensity can be attributed to the transferring of electrons from the conducting band of GeSi QDs to the graphene sheet. The electron transfer mechanism was confirmed by the time resolved PL measurements. For the PL enhancement, a mechanism called surface-plasmon-polariton (SPP) enhanced absorption mechanism is proposed, in which the excitation of SPP in the graphene is suggested. Due to the resonant excitation of SPP by incident light, the absorption of incident light is much enhanced at the surface region, thus leading to more exciton generation and a PL enhancement in the region. The results may be helpful to provide us a way to improve optical properties of low dimensional surface structures.

• OSTI ID: 22311061
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 2 Vol. 105; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION
ATTENUATION
COVERINGS
ELECTRON TRANSFER
ELECTRONS
EXCITATION
GERMANIUM SILICIDES
GRAPHENE
HYBRID SYSTEMS
LASER RADIATION
LAYERS
OPTICAL PROPERTIES
PHOTOLUMINESCENCE
QUANTUM DOTS
SURFACES
TIME RESOLUTION
VISIBLE RADIATION