Properties Of Spin-coated Films Research Articles

A study on the effect of the macrocycle ring size and R-group chain length on the optical properties of the CuPc thin films

Optical properties of spin-coated films of copper phthalocyanine (CuPc) are investigated by using UV–visible spectroscopy. The absorption spectra were recorded in the UV–visible region and showed two absorption bands of the phthalocyanine molecules, namely, the Soret (B) and the Q-band. The UV–visible spectrum is used to calculate the physical parameters of the thin film under investigation such as absorption A, reflectance R, refractive index n, extinction coefficient k, optical conductivity σopt and optical band gap Eg values. The obtained refractive index and the extinction coefficient values vary from 1.5 to 2.5 and from 0.1 to 4.5, respectively. We have observed that the direct allowed gaps have been found to be 1.5 eV and 3 eV for CuPc I; 2.4 eV, 3.2 eV and 3.65 eV for CuPc II. On the other hand, for CuPc III thin films, they have been observed as 1.55 eV, 2.55 eV and 2.9 eV. Differences in optical properties are attributed to different chemical structures of the CuPc molecules in terms of their macrocycle ring size and R-group chain length.

Anthracene dopping effects on thin films properties of octakis(alkylthio) substituted lutetium bisphthalocyanine

In this work, the investigation of structural features, spectral and electrical properties of spin-coated films of substituted lutetium bisphthalocyanine Lu ( Pc ( SR )8)2, where R = - C 6 H 13 was carried out. The current-voltage characteristics of ITO/ Lu ( Pc ( SR )8)2/ Al film sandwich structures were measured over the temperature range 120–380 K. AC electrical properties, mainly the dependence of conductance and capacitance on frequency and temperature are also discussed. Structural and electrical properties of anthracene-doped Lu ( Pc ( SR )8)2, films have also been investigated. Furthermore, optical properties of thin films of pure and anthracene-doped Lu ( Pc ( SR )8)2 films were also studied using spectroscopic ellipsometry, while atomic force microscopy (AFM) was used to study changes in films' morphology of doped films and compared with that of undoped films. Doping Lu ( Pc ( SR )8)2, films with anthracene is shown to lead to an increase in films' conductivity. These studies will provide full understanding of the physical properties of the Lu ( Pc ( SR )8)2, thin films, both doped and undoped, with the aim of exploitation in electronic device applications, such as fabrication of all organic solar cells.

Influence of the dispersion medium on the properties of spin-coated Silicalite-1 films

Purified Silicalite-1 nanocrystals were dispersed in methanol, ethanol, 2-propanol and 1-butanol and Silicalite-1 films were prepared by spin-coating. The properties of the spin coated films were dependent on the dispersion medium. The influence of the different alcohols was studied by preparing films from zeolite suspensions in corresponding alcohols with four different zeolite concentrations, from 1.5 wt.% to 15 wt.%. Similar trends were obtained for the influence of the alcohols independent of the zeolite concentration. Denser films of improved ordering were obtained using the Silicalite-1 nanocrystals dispersed in methanol and 2-propanol compared to ethanol, whereas the films prepared from 1-butanol suspensions were discontinuous. The quality of the films was judged from AFM and SEM images.

Gas-sensing properties of spin-coated indium oxide film on various substrates

Indium oxide thin films were spin-coated uniformly on alumina and silicon substrates with different roughness for the fabrication of gas-sensing films by a novel method of aqueous acetic acid solution dissolving ln(\( \left( {OH} \right)_3 \) and ammonium carboxymethyl cellulose. The effects of material properties and surface morphologies of the substrate on film formation and gas-sensing properties of the spin-coated films were studied for various kinds of substrates. Gas-sensing properties including sensitivity, selectivity and the rates of response and recovery were found to be strongly dependent on the kind of substrate and the surface roughness of the substrate as well as film thickness and operating temperature.