New columnar Zn-phthalocyanine designed for electronic applications.
Columnar liquid crystals are composed of disk-shaped aromatic molecules surrounded by flexible side chains, where molecules self-assemble in columns and thereby form large surface-oriented domains. These systems are known for their good charge and exciton transport along the columns, with mobilities approaching those of aromatic single crystals. Such semiconducting materials are promising for devices applications, since the output efficiency can be tuned by properly aligning columns. In the work presented here, the synthesis and characterization of a new Zn-phthalocyanine (ZnPc) is described which exhibits remarkable properties, such as hexagonal columnar order, achieved by cooling down from the isotropic phase to room temperature. Such order was confirmed by optical microscopy and X-ray diffraction experiments. Diodes were constructed using spin-coated films, and the conductive properties were investigated by current versus voltage analysis, where mobilities of 10(-3) and 10(-2) cm(2)/(V s) were obtained for the nonannealed and annealed films, respectively.
Departamento de Física, Universidade Federal de Santa Catarina-UFSC, 88040-900 Florianópolis, SC, Brazil. bechtold@fsc.ufsc.br
Ivan H
IH
Bechtold
Juliana
J
Eccher
Gregório C
GC
Faria
Hugo
H
Gallardo
Fernando
F
Molin
Nicholas R S
NR
Gobo
Kleber T
KT
de Oliveira
Heinz
H
von Seggern