Publication Type |
Journal Article |
School or College |
College of Science |
Department |
Physics |
Creator |
Lupton, John Mark |
Other Author |
Samuel, I. D. W.; Burn, P. L. |
Title |
Origin of spectral broadening in amorphous π-conjugated amorphous semiconductors |
Date |
2002-10 |
Description |
We present a study of the picosecond fluorescence dynamics of p-conjugated semiconducting organic dendrimers in the solid state. By varying the degree of branching within the dendrons, referred to as the dendrimer generation, a control of intermolecular spacing of the emissive core and therefore of the lattice parameter for Forster-type energy transfer is achieved. This allows a distinction between spectral diffusion and excimer formation as the two main sources of spectral broadening in organic semiconductors. Whereas Forstertype dispersive spectral relaxation is independent of temperature but strongly dependent on the interchromophore distance, excimer formation is also strongly thermally activated due to temperature-dependent conformational changes and the influence of thermally activated dynamic disorder. The rapid spectral diffusion allows a determination of the excimer rise in the emission, which is shown to have a profound impact on the steady state luminescence properties of dendrimer films. We show that the dendrimer generation not only allows a microscopic control of intermolecular interactions but also a direct control of the rate of spectral diffusion. Implications for the design of novel materials for optoelectronic devices are discussed. |
Type |
Text |
Publisher |
American Physical Society |
Journal Title |
Physical Review B |
Volume |
66 |
Issue |
15 |
DOI |
10.1103/PhysRevB.66.155206 |
citatation_issn |
0163-1829 |
Subject |
pi-conjugated polymers; pi-conjugated semiconductors; Spectral broadening; Solid state; Picosecond fluorescence dynamics |
Subject LCSH |
Amorphous semiconductors -- Optical properties; Dendrimers; Dendrimers -- Optical properties |
Language |
eng |
Bibliographic Citation |
Lupton, J. M., Samuel, I. D. W., & Burn, P. L. (2002). Origin of spectral broadening in amorphous π-conjugated amorphous semiconductors. Physical Review B, 66(15), 155206. |
Rights Management |
(c) American Physical Society http://dx.doi.org/10.1103/PhysRevB.66.155206 |
Format Medium |
application/pdf |
Format Extent |
88,305 bytes |
Identifier |
ir-main,11896 |
ARK |
ark:/87278/s6v12phc |
Setname |
ir_uspace |
ID |
707109 |
Reference URL |
https://collections.lib.utah.edu/ark:/87278/s6v12phc |