Theoretical studies of molecular orientation and charge recombination in poly-paraphenylenevinylene light-emitting diodes

Poly-paraphenylenevinylene (PPV), a material used in organic light-emitting diodes (OLEDs), for which improving the efficiency is an important issue. In general, the molecular orientations of organic compounds in the crystal form are an essential factor determining electron and hole transfer, which...

Full description

Saved in:
Bibliographic Details
Published in:Physical chemistry chemical physics : PCCP 2015-08, Vol.17 (32), p.20923-20931
Main Authors: Aikawa, Koharu, Sumita, Masato, Shimodo, Yasuyo, Morihashi, Kenji
Format: Article
Language:English
Subjects:
Computational efficiency
Crystal structure
Density
Dimers
Light
Mathematical analysis
Molecular Structure
Organic compounds
Organic light emitting diodes
Orientation
Polyvinyls - chemistry
Quantum Theory
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Poly-paraphenylenevinylene (PPV), a material used in organic light-emitting diodes (OLEDs), for which improving the efficiency is an important issue. In general, the molecular orientations of organic compounds in the crystal form are an essential factor determining electron and hole transfer, which are closely related to the efficiency of OLEDs. We have investigated the effects of the rotation of each molecule and the intermolecular distance in the dimer system of PPV, which consists of donor and acceptor molecules, on its charge-recombination process by performing constrained density functional calculations. Starting from the structure of the crystal, it was clarified that the rotation of the donor decreases the charge-recombination factor, to nearly zero, while that of the acceptor increases it to about 10(6) s(-1). We found that this is caused by the repulsive interaction between the donor and acceptor molecules and the formation of a transport pathway resulting from the acceptor rotation.
ISSN:1463-9076
1463-9084
DOI:10.1039/c5cp03235k