Second order nonlinear optical networks with excellent poling stability from a new trifunctional thiophene based chromophore

• Published in: Organic electronics Vol. 10; no. 1; pp. 53 - 60
• Main Authors: Borbone, Fabio, Caruso, Ugo, Diana, Rosita, Panunzi, Barbara, Roviello, Antonio, Tingoli, Marco, Tuzi, Angela
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-02-2009; Elsevier
• Subjects: Applied sciences; Crosslinked material; Electrical, magnetic and optical properties; Exact sciences and technology; NLO properties; Organic polymers; Physicochemistry of polymers; Properties and characterization; Thiophene dye; 61.25.hp; Thiophene dye; 82.35.Ej; Crosslinked material; 81.05.Zx; NLO properties; Second harmonic generation; Dyes; Non linear optics; Thermal stability; Three dimensional model; Crosslinked polymer; Dipole; Optical material; Thiophene polymer; Chemical synthesis; Active material; Chromophore
• ISSN: 1566-1199; 1878-5530
• DOI: 10.1016/j.orgel.2008.10.004

Two new trifunctional thiophene based dyes suited for crosslinking were synthesised from the same structural core, i.e. 4-[[5-[(4-nitrophenyl)azo]-2-thienyl]azo]benzenamine. Crystal structure and second order nonlinear optical properties were determined on a related difunctional dye that can be considered as a representative and simplified model of the trifunctional compounds, determining on it the
μβ value of 4950
×
10
−48
esu (6111
×
10
−80
C
2
m
4
V
−2).
The presence of three acrylic or hydroxyl functional groups in the dyes allowed to incorporate the chromophoric fragment into two different kinds of crosslinked materials possessing “frozen” long-lasting dipole order. The traditional guest-host approach used for one of them was exceeded by covalently anchoring the chromophore to a functionalised polymer in a three-dimensional unique network. In this way a promising NLO active material was obtained. The value of the
d
33 coefficient (determined by SHG measurement using the Maker fringe technique) was 11
pm/V for the poled/crosslinked film. Very good thermal and temporal stability of the chromophore poling-induced dipole alignment was attained.