Infrared (IR) p-polarized multiple-angle incidence resolution spectrometry (pMAIRS) is a useful spectroscopic tool for revealing the molecular anisotropic structure in a thin film, which is used for the molecular orientation analysis of many functionalized organic thin films. Infrared pMAIRS provides both in-plane (IP) and out-of-plane (OP) vibrational mode spectra, which are influenced by the choice of the angles of incidence, i.e., angle set. To obtain quantitatively reliable pMAIRS spectra, therefore, the optimal angle set must be revealed. In a former study, an optimization study was carried out on a silicon substrate by using the band intensity ratio of the IP and OP spectra of highly oriented molecules in a thin film, which has a problem that the optimized results cannot be used for another substrate. In the present study, a totally new idea using an optically isotropic thin film as a standard sample is proposed to comprehensively explore the optimal angle set on various substrates: the band shift due to the Berreman effect of a strongly absorbing compound is used, instead of the band intensity. This new approach makes the pMAIRS calibration for various substrates a much easier task. With the optimal angle set, the molecular orientation angle in the film calculated by the pMAIRS spectra is also found to be reliable quantitatively. This technique opens a user-friendly way to a reliable molecular orientation analysis in an ultrathin film using IR pMAIRS.

The performance of an organic electronic device is significantly influenced by the anisotropic molecular structure in the film, which has long been difficult to predict especially for a solution process. In the present study, a zinc tetraphenylporphyrin (ZnTPP) thin film prepared by a solution process was chosen to comprehensively explore the molecular-arrangement mechanism as a function of representative film-preparation parameters: solvent, film-preparation technique, and thermal annealing. The anisotropic structure was first analyzed by using a combination of infrared p-polarized multiple-angle incidence resolution spectrometry (pMAIRS) and grazing incidence X-ray diffraction (GIXD), which readily revealed the molecular orientation and crystal structure, respectively. As a result, the real dominant factor was found to be the evaporation time of the solvent that determines the initial two different molecular arrangements, types-I and -II, while the thermal annealing was found to play an additional role of improving the molecular order. The correlation between the molecular orientation and the crystal structure was also revealed through the individual orientation analysis of the porphyrin and phenyl rings.

The powerful combination of p-polarized multiple-angle incidence resolution spectroscopy (pMAIRS) and grazing incidence X-ray diffraction (GIXD) is applied to the structural characterization of zinc tetraphenylporphyrin (ZnTPP) in vapor-deposited films as a function of the deposition rate. The deposition rate is revealed to have an impact on the initial film structure and its conversion by thermal annealing. The pMAIRS spectra reveal that a fast deposition rate yields a kinetically restricted amorphous film of ZnTPP having a “face-on orientation”, which is readily discriminated from another “randomly oriented” amorphous film generated at a slow deposition rate. In addition, the GIXD patterns reveal that the film grown at a slow deposition rate involves a minor component of triclinic crystallites. The different initial film structure significantly influences the thermal conversion of ZnTPP films. The randomly oriented amorphous aggregates with the triclinic crystallite seeds are converted to the thermodynamically stable phase (monoclinic) via the metastable triclinic phase. The kinetically restricted structure, on the other hand, is followed by a simple thermal conversion: the molecules are directly converted to the monoclinic one rather than the triclinic one.

HighlightsHexachloro-and hexaiodosubnaphthalocyanine boron chloride were prepared. HOMO/LUMO levels were stabilized by 0.4 eV due to electronic effects of chlorine.Chlorine atoms reduced the dipole moment to lead to non-polar nature.Hexaiodosubnaphthalocyanine showed a reduced fluorescence quantum yield. AbstractChloroboron(III) hexachloro-and hexaiodosubnaphthalocyanines were prepared, and their solubility, © 2016. This manuscript version is made available under the Elsevier user license electronic absorption spectroscopy, fluorescence emission spectroscopy and HOMO/LUMO energy levels were evaluated. These subnaphthalocyanines showed lower HOMO/LUMO energies than the parent subnaphthalocyanine by 0.13 -0.39 eV. The optical band gap decreased in the order:hexafluoro-> hexachloro-> unsubstituted > hexaiodo-subnaphthalocyanine. Fluorescence quantum yield of hexaiodosubnaphthalocyanine was 0.05, significantly lower than those of the parent, hexafluoro-and hexachloro-subnaphthalocyanines whose quantum yields ranged from 0.2 to 0.22, indicating that the heavy atom effects of iodine work effectively.was slowly added dropwise at -78 °C under Ar. The reaction mixture was warmed up to room temperature, and refluxed overnight. An aqueous solution of NaOH (10%, 100 mL) was added, followed by the addition of water (150 mL) and THF (300 mL). The organic layer was separated.The aqueous layer was extracted with THF three times and the THF layer was combined with the organic layer. The combined organic layer was washed with saturated aqueous NaCl three times and the solvent was evaporated. The white solid was washed with hexane and dichloromethane: 28.8 g, 84 % yield. mp: 92-95 °C. 1 H NMR data matched published data. 22

The behavior of the partial pressure of SiF4, a byproduct in fluorine-based plasma etching, has been measured in real-time using a method based on Laser　Absorption Spectroscopy (LAS). The partial pressure of SiF4 is highly correlated　with the etch rate of SiO2 (R2 = 0.999). Etch endpoints were clearly observed　from the signal transitions, whose period indicate the etch rate uniformity. In　addition, integrating the partial pressure of SiF4 with respect to time is correlated　with the number of Si atoms etched regardless of the composition of the etched materials. Specifically, Si, SiO2 and Si3N4 were examined in this work. Based on　the strong relationship between the measured SiF4 partial pressure and the　etching profiles, real-time monitoring by LAS is useful for the prediction of etch　profiles.