Microcrystalline films

This technique of forming semiconducting films by direct oxidation-reduction is used to grow highly microcrystalline films directly on the copper or silver substrate. These films show a metallic sheen and can be grown to a thickness of 10 ym in a... 

It has been reported that Chi a in both microcrystalline films (5,10) and monolayer assemblies (23) are fairly stable over long periods of time. 

The organic matrix follows the same pattern. By means of electron diffraction analysis it can be shown that the protein matrix is and remains crystalline and that the structural order of the diffraction pattern is that of a microcrystalline film of gold (Fig. 23)224). It is remarkable that the matrix proteins in other species also produce a single crystal spot pattern. This implies that isolated pieces of organic matrix which are in the order of a few microns thick represent single crystals. Whatever the term single crystal" may mean to the various researchers43, in the context... 

Upon irradiation of an IPCT band in degassed condition (/.ex > 365 nm), the color of both LB films changed from pale yellow to blue. The UV/vis absorption spectrum after irradiation of LB films with 120 monolayers is shown in Fig. 14, which is characteristic of 4,4 -bipyridinium radical cation monomer [61], Colored species photogenerated in mixed LB films of AV2+/AA or HV2+/AA systems decayed almost exponentially in the dark in vacuo with a lifetime of about 4 hr at 20°C [38,39], The lifetime of 4,4 -bipyridinium radical cations in LB films was almost the same as that in microcrystalline films [36], which indicated the microenvironment around photogenerated radical cations in LB films... 

Early studies (Reimer et al., 1980) indicated a broad Gaussian component superimposed on a narrower Gaussian, but most recent studies (Reimer et al., 198 lb Carlos and Taylor, 1980,1982b Taylor and Carlos, 1980 Jefirey and Lowry, 1981) suggest that the narrow line has a Lorentzian shape. Microcrystalline films of Si H also exhibit a broad Gaussian superimposed on a narrower Lorentzian line (Kumeda et al., 1983). This fact demonstrates that the microstructure that gives rise to the two different sites exists in both the crystalline and amorphous forms. All studies confirm that the widths of the two lines are governed by the dipolar term [Eq. (3)] in the Hamiltonian. 

Lee and Meyer (2000) produced microcrystalline films with thicknesses of 2-5 pm made from LaCls doped BaTiOj that showed a good response to CO2 gas. A paste was screen-printed onto a sensor substrate surface and then dried at 80°C. The substrate was subsequently heated at 750°C for 20 minutes. Materials with a range of compositions were tested in air with 1% CO2 content. The greatest response was obtained with BaTiOs- with 10 weight percent LaCls at an operating temperature of 550°C. Sensor responses were also found to be rapid under these conditions (Fig. 13.9). 

Zen et al. synthesized a pentathiophene-based swivel cruciform (76, Figure 16.33), which allows rotation between the cruciform arms [143]. Homogeneous microcrystalline films were processed from solution, and field effect transistors based on this dimer afforded hole mobilities up to 0.012 cm V s . Recently, Cravino et al. demonstrated that high hole mobilities can be obtained with an amorphous oligomer that contains a triarylamine (TAA) core with hexyl-terminated terthiophene arms (77) [144], Hole mobilities up to 0.01 cm V s were measured for vapor-deposited Aims. Furthermore, Saragi et al. compared the field effect mobility of a TAA oligomer series and their spiro-linked analogues [145], All compounds... 

Most of the published work with diamond electrodes has involved the use of microcrystalline films [19,22,26-128]. Material characterization for the purpose of verifying film quality is an important component of any... 

Figure 8 shows visible-Raman spectra for moderately boron-doped ( — 10 cm ) microcrystalline and nanocrystalline diamond thin films. The spectrum for the microcrystalline film consists of the one-phonon diamond line centered at 1333 cm The line width (FWHM) is ca. 10 cm and, to a first approximation, is inversely related to the phonon lifetime [123,130]. The line position is negligibly shifted from that for a reference... 

Origin of the Photoinduced Optical Second Harmonic Generation Arising in N-Phenyl Microcrystalline Films. 

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