In:
Japanese Journal of Applied Physics, IOP Publishing, Vol. 38, No. 7R ( 1999-07-01), p. 4056-
Abstract:
The absorption and electroabsorption (EA) spectra for 4-(N,N-diethylamino)-β-nitrostyrene (DEANST)-doped poly(methyl methacrylate) (PMMA) films in the dopant concentration range of 0.1–40 wt% were measured.
Dispersion of the third-order nonlinear optical susceptibility χ (3) (-ω; 0,0,ω) at each concentration was determined. In addition, the static polarizability change Δα and the static dipole-moment change Δµ were evaluated.
Furthermore, the picosecond emission-decay profiles and the time-resolved emission spectra for 0.1–40 wt% DEANST-doped PMMA films were measured. From the experimental results, it was concluded that DEANST molecules in PMMA films aggregate at concentrations over 5 wt%.
This aggregation gives rise to two new absorption bands. The intermolecular interaction affected by aggregation causes a decrease in Δµ, in the average effective third-order molecular hyperpolarizability 〈 γ(-ω;0,0,ω) 〉 eff , and in the nonproportional behavior in |χ (3) (-ω;0,0,ω)| with increasing dopant concentration.
Furthermore, this aggregation explains the absorption spectral change, the EA spectral shift and the existence of two emission-decay constants with concentration. Finally, the average aggregation number of DEANST molecules was evaluated to be two, which suggests that DEANST molecules in the PMMA film form a dimer at concentrations over 5 wt%.
Type of Medium:
Online Resource
ISSN:
0021-4922
,
1347-4065
DOI:
10.1143/JJAP.38.4056
Language:
Unknown
Publisher:
IOP Publishing
Publication Date:
1999
detail.hit.zdb_id:
218223-3
detail.hit.zdb_id:
797294-5
detail.hit.zdb_id:
2006801-3
detail.hit.zdb_id:
797295-7
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