Unraveling the luminescence signatures of chemical defects in polyethylene

Journal Article · Mon Sep 28 00:00:00 EDT 2015 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4931986· OSTI ID:22489661

Chen, Lihua; Tran, Huan Doan; Wang, Chenchen; Ramprasad, Rampi ^[1]

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1. Department of Materials Science and Engineering, Institute of Materials Science, University of Connecticut, 97 North Eagleville Road, Storrs, Connecticut 06269 (United States)

Chemical defects in polyethylene (PE) can deleteriously downgrade its electrical properties and performance. Although these defects usually leave spectroscopic signatures in terms of characteristic luminescence peaks, it is nontrivial to make unambiguous assignments of the peaks to specific defect types. In this work, we go beyond traditional density functional theory calculations to determine intra-defect state transition and charge recombination process derived emission and absorption energies in PE. By calculating the total energy differences of the neutral defect at excited and ground states, the emission energies from intra-defect state transition are obtained, reasonably explaining the photoluminescence peaks in PE. In order to study the luminescence emitted in charge recombination processes, we characterize PE defect levels in terms of thermodynamic and optical charge transition levels that involve total energy calculations of neutral and charged defects. Calculations are performed at several levels of theory including those involving (semi)local and hybrid electron exchange-correlation functionals, and many-body perturbation theory. With these critical elements, the emission energies are computed and further used to clarify and confirm the origins of the observed electroluminescence and thermoluminescence peaks.

• OSTI ID: 22489661
• Journal Information: Journal of Chemical Physics, Vol. 143, Issue 12; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ABSORPTION
ALLOCATIONS
DEFECTS
DENSITY FUNCTIONAL METHOD
ELECTRICAL PROPERTIES
ELECTROLUMINESCENCE
ELECTRON EXCHANGE
GROUND STATES
HYBRIDIZATION
MANY-BODY PROBLEM
PEAKS
PERTURBATION THEORY
PHOTOLUMINESCENCE
POLYETHYLENES
RECOMBINATION
THERMOLUMINESCENCE