Synthetic Metals 144 (2004) 7–11 Morphology of poly(p-phenylenevinylene) thin films prepared directly on the surface of silicon wafers by the chemical vapor deposition polymerization Kyungkon Kim a , Mi Yoon Jung a , Guo Lun Zhong a , Jung-Il Jin a,∗ , Tae Young Kim b , Dong June Ahn b a Division of Chemistry and Molecular and Bioengineering, Center for Electro- and Photo-Responsive Molecules, Korea University, Seoul 136-701, South Korea b Department of Chemical Engineering, Korea University, Seoul 136-701, South Korea Received 2 January 2004; accepted 5 January 2004 Available online 11 Marhc 2004 Abstract The chemical vapor deposition polymerization (CVDP) of , ′ -dichloro-p-xylene on the (0 0 1) plane of silicon wafer surface followed by thermal dehydrochlorination produced PPV nanofilms in which the polymer chains are found to be in highly ordered morphology. The same CVDP polymerization of , ′ -dichloro-p-xylene on the quartz surface, however, produced disordered polymer chains. The morphology and chain orientations were studied by X-ray diffractometry and polarized UV-Vis absorption and polarizesd photoluminescence spectroscopies. The angle dependence of IR refractive absorption spectra of the PPV films also were studied. © 2004 Elsevier B.V. All rights reserved. Keywords: PPV; Chemical vapor deposition polymerization; CVD; Morphology; Polarized UV-Vis absorption; Polarized PL; IRRAS 1. Introduction In future, polyconjugated polymers can be useful for various applications in nano-sized organic electro- or optic-devices. Many of polyconjugated polymers, however, are insoluble and infusible and, thus, are very difficult to be fabricated to desired shapes and architectures having a nano dimensions. This problem can be circumvented by the chemical vapor deposition polymerization (CVDP) method [1] if a proper monomer and reaction condition can be found. The CVDP method is unique in that the activated species formed by pyrolysis of a monomerat an elevated temperature in the gas phase undergo self-addition on cold substrate surface to produce the final polymer or a precursor polymer that can be transformed, usually ther- mally, to the final polymer. This method does not require the use of any solvent and additional chemicals during the polymerization process and have excellent gap-filling and step coverage properties. Moreover, since synthesis can be performed directly on the surface of desired substrates, we ∗ Corresponding author. E-mail address: jijin@korea.ac.kr (J.-I. Jin). can obtain uncontaminated polymers in various shapes. In addition, the CVDP method can be successfully utilized for the preparation of the polymer samples of nano structure and dimensions. Poly(p-phenylenevinylene), PPV, and copolymers belongs to a class of polyconjugated polymers revealing many inter- esting properties such as electrical conductivity [2–4], photo- and electroluminescence [5], and nonlinear optical behavior [6]. PPV can also be thermally converted to graphitic or car- bonaceous products [7]. Recently, we [8] reported that PPV nanofilms, nanotubes and nanorods can be easily prepared by performing the chemical vapor deposition polymerization of , ′ -dichloro-p-xylene (Scheme 1) on the inner suface of pores of organic or inorganic membranes. Staring et al. [9] and Shäfer et al. [10] earlier obtained thin films of PPV by CVDP method. They studied electroluminescence properties of those PPV films. Iwatsuki et al. [11] could prepare PPV by CVDP of dichlorocyclophane. Vaeth and Jensen [12] sug- gested that control of the chain orientation of the polymer can be achieved with the CVD method. They [13] also stud- ied in detail the reaction mechanism of this polymerization method. Moreover, the nano objects of PPV could be con- verted thermally to carbonaceous nanotubes and nanorods. 0379-6779/$ – see front matter © 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.synthmet.2004.01.004