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Formation of Si(phthalocyaninato)(OH) 2 and [Si(phthalocyaninato)O]~ films and
their optical and electrical properties
M. YUDASAKA
Department of Materials Chemistry, Faculty of Engineering, Yokohama National University, Yokohama
(Japan)
M. KAWAI
The Institute of Physical and Chemical Research, Wako Saitama (Japan)
S. KURITAAND K. NAKANISHI
Department of Materials Chemistry, Faculty of Engineering, Yokohama National University, Yokohama
(Japan)
Y. KUWAE
Canon Incorporation, Atsugi Kanagawa (Japan)
(Received February27, 1987;accepted May8, 1987)
Films of Si(Pc)(OH) 2 (where Pc stands for phthalocyaninato) and [Si(Pc)O]n
were formed selectively by evaporating Si(Pc)(OH)2 and varying the substrate
temperature T~. Si(Pc)(OH)2 films formed at T~ < 200°C and [Si(Pc)O]n films
formed at T~ > 240 °C.
The absorption spectra and action spectra of the photocurrent for Si(Pc)(OH)2
films in the visible and near-IR regions show marked dependences on T~ owing to
differences in the degrees of crystallization and orientation and in the intermolecular
interaction of hydrogen bonds through --OH groups.
The photoconductivity of I-Si(Pc)O], films is much less than that of Si(Pc)(OH)2
films.
[Si(Pc)O]n is known as a cofaciallyjoined metallomacrocylic polymer made by
the dehydration-condensation of Si(Pc)(OH) 2 (ref. 1). Because of its thermal and
chemical stabilities and electrical properties t-5, [Si(Pc)O]~ has been expected to be a
favourable organic material for electrical conductors. Si(Pc)(OH)2 is considered to
be a hopeful material for photoelectric devices which are sensitive in the near-IR
wavelength region 6, although the thermal stability of Si(Pc)(OH)2 is worse than that
of [Si(Pc)O]~.
The possibility of utilizing these compounds in electronic devices has been
enhanced since the preparation of thin films of [Si(Pc)O]~ and Si(Pc)(OH)2 has been
demonstrated. One of us (Y.K.) has pointed out that a thin film of [Si(Pc)O]n is
formed by heating a film of the monomer Si(Pc)(OH)2 (ref. 7). Kobayashi et al. a
prepared epitaxial films of some phthalocyanine monomers and polymers including
Si(Pc)(OH)2 and [Si(Pc)O]. and characterized the structures of these filmsa.
In this study we investigate the substrate temperature T~ dependence of the
properties of films obtained by the evaporation of Si(Pc)(OH)2. It is found that
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