Aggregation in hemicyanine dye Langmuir-Blodgett films: ultraviolet-visible absorption and second harmonic generation studies

1992 ◽  
Vol 96 (7) ◽  
pp. 2801-2804 ◽  
Author(s):  
Michael A. Carpenter ◽  
Craig S. Willand ◽  
Thomas L. Penner ◽  
David J. Williams ◽  
Shaul Mukamel
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Visible Absorption ◽  
Langmuir Blodgett ◽  
Hemicyanine Dye ◽  
Langmuir Blodgett Films

ENHANCED SHG IN POLYELECTROLYTE COMPLEXED HEMICYANINE DYE LANGMUIR–BLODGETT FILMS

2004 ◽  
Vol 13 (03n04) ◽  
pp. 347-353 ◽  
Author(s):  
M. SHARATH CHANDRA ◽  
Y. OGATA ◽  
J. KAWAMATA ◽  
T. P. RADHAKRISHNAN
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Convenient Method ◽  
Second Harmonic ◽  
Water Interface ◽  
Langmuir Film ◽  
Langmuir Blodgett ◽  
Air Water Interface ◽  
Hemicyanine Dye ◽  
Langmuir Blodgett Films

Complexation of ionic amphiphiles at the air–water interface by polyelectrolytes in the subphase has a pronounced effect of stabilization and deaggregation on the amphiphiles. We have effectively utilized the latter in the case of a hemicyanine dye based amphiphile. The aggregation of these amphiphiles is influenced by the rate of equilibration of the Langmuir film and the introduction of polyelectrolytes in the subphase is found to be a convenient method to suppress the aggregation. Langmuir–Blodgett films obtained by transfer of the polyelectrolyte complexed amphiphiles show enhanced second harmonic generation.

Second Harmonic Generation in Langmuir-Blodgett Films of N-Docosyl-4-Nitroaniline

1991 ◽  
pp. 157-166
Author(s):  
T. Geisler ◽  
S. Rosenkilde ◽  
W. M. K. P. Wijekoon ◽  
P. N. Prasad ◽  
P. S. Ramanujam
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Langmuir Blodgett ◽  
Langmuir Blodgett Films

2,4-Bis[4-(dihexadecylamino)-2-hydroxyphenyl]-squaraine: Second-Harmonic Generation from Langmuir - Blodgett Monolayers of a Centro-symmetric Dye in which the Chromophores are Isolated from the Substrate

1999 ◽  
Vol 52 (1) ◽  
pp. 37 ◽  
Author(s):  
Geoffrey J. Ashwell ◽  
Patricia C. Williamson ◽  
Gurmit S. Bahra ◽  
Christopher R. Brown
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Blodgett Film ◽  
Langmuir Blodgett ◽  
Hydrophobic Barrier ◽  
Hemicyanine Dye ◽  
Donor Acceptor ◽  
The Mean ◽  
Donor Moiety

2,4-Bis[4-(dihexadecylamino)-2-hydroxyphenyl]squaraine is vertically oriented in the Langmuir–Blodgett film and the chromophore layer is separated from the glass substrate by the hydrophobic dihexadecylamino groups. The Langmuir–Blodgett monolayer exhibits moderately strong second-harmonic generation (SHG) with an effective susceptibility of c. 10 pm V-1 at 1064 nm and an intensity, relative to the mean SHG from films of the extensively studied hemicyanine dye (E)-4-[2-(4-dimethylaminophenyl)ethenyl]-N-docosylpyridinium bromide, of c. 0·3. The SHG cannot arise from the polarization of the dye by the underlying substrate because the conjugated donor-(acceptor)-donor moiety is separated by a 2 nm thick hydrophobic barrier. Instead, the non-linear optical behaviour is attributed to a non-centrosymmetric aggregate structure.

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