Disorder influenced absorption line shapes of a chromophore coupled to two-level systems
We have carried out a theoretical and numerical study of disorder-induced changes in the absorption line shape of a chromophore embedded in a host matrix. The stochastic sudden jump model is employed wherein the host matrix molecules are treated as noninteracting two-level systems (TLSs) occupying p...
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sg-ntu-dr.10356-1013742023-07-14T15:54:34Z Disorder influenced absorption line shapes of a chromophore coupled to two-level systems Shenai, Prathamesh M. Chernyak, Vladimir Zhao, Yang School of Materials Science & Engineering DRNTU::Engineering We have carried out a theoretical and numerical study of disorder-induced changes in the absorption line shape of a chromophore embedded in a host matrix. The stochastic sudden jump model is employed wherein the host matrix molecules are treated as noninteracting two-level systems (TLSs) occupying points on a three-dimensional lattice with randomly oriented dipole moments. By systematically controlling the degree of positional disorder (α) attributed to them, a perfectly crystalline (α = 0) or a glassy environment (α = 1) or a combination of the two is obtained. The interaction between the chromophore and the TLSs is assumed to be of the dipole–dipole form. With an increase in α, the broadening of the absorption line shape was found to follow a power-law behavior. More importantly, it is revealed in the long-time limit that the resultant line shape is Gaussian in the absence of disorder but transforms to Lorentzian for a completely disordered environment. For an arbitrarily intermediate value of α, the resultant line shape can be approximately fitted by a linear combination of Gaussian and Lorentzian components. The Lorentzian profile for the disordered medium is attributed to the chomophore–TLS pairs with vanishingly small separation between them. Accepted version 2014-06-13T01:27:47Z 2019-12-06T20:37:25Z 2014-06-13T01:27:47Z 2019-12-06T20:37:25Z 2013 2013 Journal Article Shenai, P. M., Chernyak, V., & Zhao, Y. (2013). Disorder Influenced Absorption Line Shapes of a Chromophore Coupled to Two-Level Systems. Journal of Physical Chemistry A, 117(47), 12320–12331. 1089-5639 https://hdl.handle.net/10356/101374 http://hdl.handle.net/10220/19722 10.1021/jp4080042 179404 en Journal of physical chemistry A © 2013 American Chemical Society. This is the author created version of a work that has been peer reviewed and accepted for publication by Journal of Physical Chemistry A, American Chemical Society. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: http://dx.doi.org/10.1021/jp4080042. application/pdf |
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DRNTU::Engineering Shenai, Prathamesh M. Chernyak, Vladimir Zhao, Yang Disorder influenced absorption line shapes of a chromophore coupled to two-level systems |
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We have carried out a theoretical and numerical study of disorder-induced changes in the absorption line shape of a chromophore embedded in a host matrix. The stochastic sudden jump model is employed wherein the host matrix molecules are treated as noninteracting two-level systems (TLSs) occupying points on a three-dimensional lattice with randomly oriented dipole moments. By systematically controlling the degree of positional disorder (α) attributed to them, a perfectly crystalline (α = 0) or a glassy environment (α = 1) or a combination of the two is obtained. The interaction between the chromophore and the TLSs is assumed to be of the dipole–dipole form. With an increase in α, the broadening of the absorption line shape was found to follow a power-law behavior. More importantly, it is revealed in the long-time limit that the resultant line shape is Gaussian in the absence of disorder but transforms to Lorentzian for a completely disordered environment. For an arbitrarily intermediate value of α, the resultant line shape can be approximately fitted by a linear combination of Gaussian and Lorentzian components. The Lorentzian profile for the disordered medium is attributed to the chomophore–TLS pairs with vanishingly small separation between them. |
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School of Materials Science & Engineering |
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School of Materials Science & Engineering Shenai, Prathamesh M. Chernyak, Vladimir Zhao, Yang |
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Article |
author |
Shenai, Prathamesh M. Chernyak, Vladimir Zhao, Yang |
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Shenai, Prathamesh M. |
title |
Disorder influenced absorption line shapes of a chromophore coupled to two-level systems |
title_short |
Disorder influenced absorption line shapes of a chromophore coupled to two-level systems |
title_full |
Disorder influenced absorption line shapes of a chromophore coupled to two-level systems |
title_fullStr |
Disorder influenced absorption line shapes of a chromophore coupled to two-level systems |
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Disorder influenced absorption line shapes of a chromophore coupled to two-level systems |
title_sort |
disorder influenced absorption line shapes of a chromophore coupled to two-level systems |
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2014 |
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https://hdl.handle.net/10356/101374 http://hdl.handle.net/10220/19722 |
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1772825878779133952 |