Exciton autolocalization in quino-2-monomethine cyanineJ-aggregates

Malyukin, Yu. V.; Seminozhenko, V. P.; Tovmachenko, O. G.

doi:10.1007/bf02606687

Cited by 8 publications

(24 citation statements)

References 3 publications

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“…It is shown that this band (Fig. 1a) consists of two ones, which are associated with an emission of free and self-trapped excitons [8,9]. At 80 K the free and self-trapped exciton emission bands are clearly divided (Fig.…”

Section: Resultsmentioning

confidence: 94%

“…The possibility of exciton self-trapping was also discussed to explore the nonexponential luminescence decay of J-aggregates, which are characterized by a small Stokes shift [7]. The authors [7] came to the conclusion that in this On the other hand, it was shown [8,9] that at low temperature (1.5-80 K) the luminescence spectrum of amphi-PIC J-aggregates consists of two bands, one of which coincides with the absorption band, and the other one reveals the significant Stokes shift (about 1300 cm À1 ). Two bands observed were associated with the emission of free and selftrapped excitons [8,9], which states are separated by a self-trapping barrier.…”

Section: Introductionmentioning

confidence: 95%

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Co-existence of free and self-trapped excitons in J-aggregates

Malyukin

Lebedenko

Sorokin

et al. 2005

Journal of Luminescence

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Section: Resultsmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 95%

Co-existence of free and self-trapped excitons in J-aggregates

Malyukin

Lebedenko

Sorokin

et al. 2005

Journal of Luminescence

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“…In [98] it was found that the capture of such excitations by the molecules of traps, like the impurity centers in crystals, can also occur in disordered media -liquid solutions and polymers. Therefore, in spite of their weak intrinsic luminescence, J-aggregates are capable of substantially increasing it in the molecules of the traps.…”

Section: Methods Of Introduction Of Dyes Into the Polymer And Their Cmentioning

confidence: 98%

Physical and chemical problems of the creation of photostable converters of light energy on the basis of dyed polymers

Ishchenko

Grabchuk

2009

Theor Exp Chem

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The main factors affecting the degradation of dyed polymeric matrices by the action of light (conversion of light energy into thermal energy, electron phototransfer, population of triplets, aggregation of dyes, oxidation-reduction processes, interaction with oxygen, including singlet) are analyzed and classified. Their dependence on the structure of the dyes, the nature of the polymer, and the method of dyeing of the latter is examined. Criteria for the creation of lightfast dyed matrices are formulated. Special attention is directed to contemporary light-sensitive materials in which the dye is covalently bonded to the polymer and to organic-inorganic compositions based on them.Dyed polymers are widely used in laser technology [1][2][3][4][5], media for writing and recording data [6-8], solar power [9][10][11][12], and optoelectronics [12][13][14][15]. Such polymeric materials have a series of operational advantages over dyed liquid materials on account of their more simple and more convenient construction, non-toxicity, and the possibility of working over a wide temperature range (from minus to plus temperatures) and under conditions of weightlessness. However, these advantages can only be realized to the full extent in the solution of various applied problems if dyed matrices with sufficient stability to the action of light are created. The aim of the present review was therefore to analyze, classify, and generalize methods of creating such matrices. FACTORS GIVING RISE TO THE DEGRADATION OF DYED POLYMERS DURING THE ACTION OF LIGHTThe presence of absorbing microimpurities that are heated by radiation are responsible for the radiation damage of optically transparent polymers. Purification from such inclusions at the monomer stage leads to a substantial increase in the threshold of radiation damage in the obtained polymer. For instance, the purification of methylmethacrylate (MMA) by repeated slow distillation raises this threshold of polymethylmethacrylate (PMMA) from several times [16] to two orders of magnitude [17]. 0040-5760/09/4503-0143

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“…However, the luminescence spectra of amphi-PIC J-aggregates clear demonstrate two separate bands that belong to the emission of free and self-trapped excitons [26][27][28]. It points to the existence of the energy barrier which stabilizes free excitons with one-dimensional movement.…”

mentioning

confidence: 99%

“…Formation of self-trapped states is suppressed by increasing water content in a DMF-W matrix [26][27][28] or by adding a cationic surfactant CPB into a DMF-W matrix (Fig. 2b).…”

mentioning

confidence: 99%

Coexistence of free and self‐trapped excitons in disordered J‐aggregates

Malyukin

2006

Phys. Status Solidi (c)

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PACS 71.35.AaCoexistence of free and self-trapped exciton in amphi-PIC J-aggregates is proved by the numerous experimental data presented and analyzed. The self-trapping states are shown to originate from delocalized exciton states exhibiting collective nature of polaronic relaxation. The strong correlation between the efficiency of exciton self-trapping and static disorder degree in J-aggregates has been shown. In amphi-PIC J-aggregates the polaronic state formation found out to require the overcoming an energy barrier which appears for quasi-one-dimension system as a result of combination of one-dimensional exciton motion and three-dimension lattice deformation. [16,17]. Despite relatively long history of J-aggregate investigation, some questions concerning exciton dynamics governed by polaronic relaxation are not fully understood.In many cases the absorption and luminescence properties of J-aggregates are well described within the one-dimensional Frenkel exciton model for a rigid chain with static disorder [1][2][3][4][5][6]. But, the chain could be deformable and if the constant of exciton-lattice coupling is strong enough, the exciton can create a chain distortion that produces a new polaronic state below the exciton band bottom. This phenomenon is called self-trapping [18]. The self-trapping pattern of the exciton interacting with a lattice via short-range potential depends strongly on the exciton motion dimension [19][20][21]. According to the Rashba-Toyozava theory, the excitons characterized by one-dimensional motion are always self-trapped. So, free excitons are unstable irrespective of the magnitude of exciton-lattice coupling and there is no any energy barrier which separates free and self-trapped exciton states [18][19][20][21]. The spatial extension of

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Exciton autolocalization in quino-2-monomethine cyanineJ-aggregates

Cited by 8 publications

References 3 publications

Co-existence of free and self-trapped excitons in J-aggregates

Co-existence of free and self-trapped excitons in J-aggregates

Physical and chemical problems of the creation of photostable converters of light energy on the basis of dyed polymers

Coexistence of free and self‐trapped excitons in disordered J‐aggregates

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