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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Order Induced Charge Carrier Mobility Enhancement in Columnar Liquid Crystal Diodes

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Author(s):
Eccher, Juliana [1, 2] ; Faria, Gregorio C. [3] ; Bock, Harald [4, 5] ; von Seggern, Heinz [2] ; Bechtold, Ivan H. [1]
Total Authors: 5
Affiliation:
[1] Univ Fed Santa Catarina, Dept Fis, BR-88040900 Florianopolis, SC - Brazil
[2] Tech Univ Darmstadt, Inst Mat Sci, Dept Elect Mat, D-64287 Darmstadt - Germany
[3] Univ Sao Paulo, Inst Fis Sao Paulo, BR-13560970 Sao Carlos, SP - Brazil
[4] Univ Bordeaux, Ctr Rech Paul Pascal, F-33600 Pessac - France
[5] CNRS, F-33600 Pessac - France
Total Affiliations: 5
Document type: Journal article
Source: ACS APPLIED MATERIALS & INTERFACES; v. 5, n. 22, p. 11935-11943, NOV 27 2013.
Web of Science Citations: 54
Abstract

Discotic molecules comprising a rigid aromatic core and flexible side chains have been promisingly applied in OLEDs as self-organizing organic semiconductors. Due to their potentially high charge carrier mobility along the columns, device performance can be readily improved by proper alignment of columns throughout the bulk. In the present work, the charge mobility was increased by 5 orders of magnitude due to homeotropic columnar ordering induced by the boundary interfaces during thermal annealing in the mesophase. State-of-the-art diodes were fabricated using spin-coated films whose homeotropic alignment with formation of hexagonal germs was observed by polarizing optical microscopy. The photophysical properties showed drastic changes at the mesophase-isotropic transition, which is supported by the gain of order observed by X-ray diffraction. The electrical properties were investigated by modeling the current-voltage characteristics by a space-charge-limited current transport with a field dependent mobility. (AU)

FAPESP's process: 08/01935-5 - Correlation between electric and optical properties with molecular dynamics and physical structure of films and organic devices of polyfluorenes and its derivatives
Grantee:Gregório Couto Faria
Support type: Scholarships in Brazil - Doctorate
FAPESP's process: 12/01303-4 - Structural and morphological characterization of conjugated polymer films for application on high performance photo-voltaic devices
Grantee:Gregório Couto Faria
Support type: Scholarships in Brazil - Post-Doctorate