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Organic light-emitting diodes: theoretical understanding of highly efficient materials and development of computational methodology.

Authors :
Zhigang Shuai
Qian Peng
Source :
National Science Review. 2017, Vol. 4 Issue 2, p224-239. 16p.
Publication Year :
2017

Abstract

Theoretical understanding of organic light-emitting diodes started from the quest to the nature of the primary excitation in organic molecular and polymeric materials. We found the electron correlation strength, bond-length alternation as well as the conjugation extent have strong influences on the orderings of the lowest lying excited states through the first application of density matrix renormalization group theory to quantum chemistry. The electro-injected free carriers (with spin 1/2) can form both singlet and triplet bound states. We found that the singlet exciton formation ratio can exceed the conventional 25% spin statistics limit. We proposed a vibration correlation function formalism to evaluate the excited-state decay rates, which is shown to not only give reasonable estimations for the quantum efficiency but also a quantitative account for the aggregation-induced emission (AIE). It is suggested to unravel the AIE mechanism through resonance Raman spectroscopy. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
20955138
Volume :
4
Issue :
2
Database :
Academic Search Index
Journal :
National Science Review
Publication Type :
Academic Journal
Accession number :
123333711
Full Text :
https://doi.org/10.1093/nsr/nww024