DIELECTRIC-PROPERTIES OF CALIXARENE THIN-FILMS IN A LARGE FREQUENCY-RANGE

A useful trend that has emerged in recent years is the attempt to use molecular oligomers as active materials in electronic, optoelectronic and sensing devices. Calixarenes are a comparatively new cyclic supramolecular material. Thin calix[6]arene films are deposited using a thermal evaporating method, and thermal annealings of samples are performed under different atmospheric conditions. D.c. and a.c. conductivities are measured in the large frequency range 10(-3)-10(6) Hz. The electronic transport mechanism in calixarene is discussed in terms of Mott hopping in samples. At ambient temperature, the a.c. conductivity can be expressed by sigma(ac)(omega)=A omega(5), where the slope s is close to unity and its value decreases with decrease in frequency. The dielectric constant in this region shows a very weak frequency dependence.