TY - JOUR
T1 - Shape Matters
T2 - Effect of 1D, 2D, and 3D Isovolumetric Quantum Confinement in Semiconductor Nanoparticles
AU - Scher, Jeremy A.
AU - Elward, Jennifer M.
AU - Chakraborty, Arindam
N1 - Funding Information:
This material is based upon work supported by the National Science Foundation under Grant No. CHE-1349892. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation Grant No. ACI-1053575. We are also grateful to Syracuse University for additional computational and financial support.
Publisher Copyright:
© 2016 American Chemical Society.
PY - 2016/11/3
Y1 - 2016/11/3
N2 - Semiconductor nanoparticles (NPs) are a class of nanoscopic materials with highly tunable optical and electronic properties. The electronic density of states of these NPs depends strongly on both shape and size and has allowed semiconductor NPs to be tailored for applications in various fields including photovoltaics, solid-state lighting, and biological labeling. This work presents investigation of the effect of shape on excitonic properties of electronically excited NPs. Specifically, this work focuses on isovolumetric NPs and addresses the question of how optical properties of NPs are impacted by isovolumetic deformation of NP shapes. The effects of three shapes, representing 1D, 2D, and 3D quantum confinement, for three sizes and four semiconductor materials (CdSe, CdS, CdTe, and PbS) were studied. The electronic excitation in these NPs was described using electron-hole (eh) quasiparticle representation, and exciton binding energies, eh-joint probabilities, and eh-separation distances were calculated using the eh explicitly correlated Hartree-Fock method. The calculations demonstrated that increased anisotropy in the confinement potential resulted in decreased exciton binding energy in the NPs. Within a specific volume, it was found that nanorods exhibited lower exciton binding energies than did nanodisks and that nanodisks exhibited lower exciton binding energies than nanospheres of identical volume. In contrast, the trend for eh-joint probability was found to be opposite that of exciton binding energies. These results demonstrate that a relatively small change in NP structure can result in a substantial change in the excitonic properties of these nanomaterials. (Graph Presented).
AB - Semiconductor nanoparticles (NPs) are a class of nanoscopic materials with highly tunable optical and electronic properties. The electronic density of states of these NPs depends strongly on both shape and size and has allowed semiconductor NPs to be tailored for applications in various fields including photovoltaics, solid-state lighting, and biological labeling. This work presents investigation of the effect of shape on excitonic properties of electronically excited NPs. Specifically, this work focuses on isovolumetric NPs and addresses the question of how optical properties of NPs are impacted by isovolumetic deformation of NP shapes. The effects of three shapes, representing 1D, 2D, and 3D quantum confinement, for three sizes and four semiconductor materials (CdSe, CdS, CdTe, and PbS) were studied. The electronic excitation in these NPs was described using electron-hole (eh) quasiparticle representation, and exciton binding energies, eh-joint probabilities, and eh-separation distances were calculated using the eh explicitly correlated Hartree-Fock method. The calculations demonstrated that increased anisotropy in the confinement potential resulted in decreased exciton binding energy in the NPs. Within a specific volume, it was found that nanorods exhibited lower exciton binding energies than did nanodisks and that nanodisks exhibited lower exciton binding energies than nanospheres of identical volume. In contrast, the trend for eh-joint probability was found to be opposite that of exciton binding energies. These results demonstrate that a relatively small change in NP structure can result in a substantial change in the excitonic properties of these nanomaterials. (Graph Presented).
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U2 - 10.1021/acs.jpcc.6b06728
DO - 10.1021/acs.jpcc.6b06728
M3 - Article
AN - SCOPUS:84994474489
SN - 1932-7447
VL - 120
SP - 24999
EP - 25009
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 43
ER -