Visualization of weak interactions between quantum dot and graphene in hybrid materials.
The mechanisms of the weak interactions within hybrid materials such as quantum dot (QD) and graphene (GR) have important implications for the design of related optoelectronic devices. We characterize the weak interactions in hybrid QD-GR systems using a non-covalent interactions approach. For a single Cd13Se13QD with a core-cage structure, the intensity of the steric repulsive strain in every Cd-Se spatial four-atom ring of the cage surface is stronger than that of the inter-core-cage structure. Van der Waals (vdW) interactions occur within the cavity of the cage and within the six-atom rings of the cage surface. The spatial repulsion strain and attractive interactions play a key role in stabilizing the structure of the monolayer graphene. Interestingly, the spatial six-atom ring of the single QD change into spatial four-atom rings of the QD in the hybrid system, accompanied by the translation of vdW interactions into steric repulsive interactions. We conclude that the vdW interactions with π extensions and the weak attractive interactions within local areas between the QD and graphene together stabilize the integral structure of the hybrid QD-GR system. These results explain of the formation mechanism and the stabilization of the components in QD-GR hybrid materials.
Department of Physics and Department of Chemistry, Liaoning University, Shenyang, 110036, P.R. China.
Shuo
S
Cao
Department of Physics and Department of Chemistry, Liaoning University, Shenyang, 110036, P.R. China.|Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing, 100083, P.R. China.|Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, Beijing, 100190, P.R. China.|Department of Physics, Shenyang Aerospace University, 110036, Shenyang, P.R. China.
Jingang
J
Wang
Department of Physics and Department of Chemistry, Liaoning University, Shenyang, 110036, P.R. China.
Yong
Y
Ding
Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing, 100083, P.R. China. mengtaosun@ustb.edu.cn.|Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, Beijing, 100190, P.R. China. mengtaosun@ustb.edu.cn.
Mengtao
M
Sun
Department of Physics and Department of Chemistry, Liaoning University, Shenyang, 110036, P.R. China. mafengcai@lnu.edu.cn.
Fengcai
F
Ma