Morphology dependence of the triplet excited state formation and absorption in polyfluorene

Title data

Hayer, Anna ; Khan, Amena L. T. ; Friend, Richard H. ; Köhler, Anna:
Morphology dependence of the triplet excited state formation and absorption in polyfluorene.
In: Physical Review B. Vol. 71 (2005) Issue 24 . - No. 241302.
ISSN 0163-1829
DOI: https://doi.org/10.1103/PhysRevB.71.241302

Official URL:

Abstract in another language

Poly(9,9-dioctylfluorene) (PFO) is widely used as a highly efficient blue-emitting polymer for light-emitting diode applications. Films of PFO are known to contain a planar β-phase or a disordered glassy phase that affects the emission characteristics. We have studied the morphology dependence of the photoinduced absorption in such PFO films and find that the T1‐Tn absorption signal differs between the two phases in energy, linewidth, and intensity. The lower intensity we observe in the β-phase as compared to the glassy phase is evidence for a lower T1 population in the former. We attribute this to firstly, reduced intersystem crossing and secondly, increased charge generation due to both more extended conjugation along the chains and higher interchain interactions in the planar, well-ordered β-phase. The reduced energy and smaller linewidth of the triplet absorption in the β-phase as compared to the glassy phase are indicative of a more delocalized Tn state and a higher degree of order in the β-phase, respectively.

Further data

Item Type:	Article in a journal
Refereed:	No
Institutions of the University:	Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics > Chair Experimental Physics II - Optoelectronics of Soft Matter > Chair Experimental Physics II - Optoelectronics of Soft Matter - Univ.-Prof. Dr. Anna Köhler Faculties Faculties > Faculty of Mathematics, Physics und Computer Science Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics > Chair Experimental Physics II - Optoelectronics of Soft Matter
Result of work at the UBT:	No
DDC Subjects:	500 Science > 530 Physics
Date Deposited:	10 Mar 2015 12:49
Last Modified:	08 Feb 2022 14:11
URI:	https://eref.uni-bayreuth.de/id/eprint/7980