a-crystalline phase poly(vinylidene fluoride) (PVDF) film was oriented uniaxially at different draw ratios. Morphological effects of orientation were investigated by X-ray diffraction and differential scanning calorimetry (DSC) measurements on the oriented samples. The dielectric loss factor was measured from 100 Hz to 1 MHz range between 80 and 400 K as a function of frequency and temperature. While the activation energy of the arelaxation transition was not affected by the orientation, it was observed that there is a linear increase in the activation energy of the b-relaxation transition with draw ratio. The relaxation time of the b-relaxation transition was more affected by the orientation process at lower temperatures.

Visible photoluminescence (PL) in anodized porous Si (PS) at room temperature has opened the way to realize different types of quantum electronics devices based on silicon technology. Such devices require a strong PL intensity and a controlled shift of the PL peak on the energy scale. Porous silicon is produced by electrochemical etching of either p-or n-type crystalline silicon. illumination is one ofthe most complicated parameters in PS formation, because it changes the properties of microporous as well as macroporous layers. It is necessary to illuminate the wafer during the anodization in order to create the holes required by the chemical reaction to form the PS. In this paper we present the results of the effects of illumination level during fabrication on the PL properties of p-type PS and it time degradation dynamics.