Low temperature sintering has become a very important research area in ceramics processing and sintering as a promising process to obtain grain size below 100nm. For electronic ceramics, low temperature sintering is particularly difficult, because not only the required microstructure but also the desired electronic properties should be obtained. In this dissertation, the effect of liquid sintering aids and particle size (micrometer and nanometer) on sintering temperature and Positive Temperature Coefficient Resistivity (PTCR) property are investigated for Ba1-xSrxTiO3 (BST) doped with 0.2-0.3mol% Sb3+ (x = 0.1,0.2,0.3,0.4 and 0.5). Different sintering aids with low melting point are used as sintering aids to decrease the sintering temperature for micrometer size BST particles. Micrometer size and nanometer size Ba1-xSrxTiO3 (BST) particles are used to demonstrate the particle size effect on the sintering temperature for semiconducting BST. To reduce the sintering temperature, three processes are developed, i.e. 1 using sol-gel nanometer size Sb3+ doped powders with a sintering aid; 2 using micrometer size powders plus a sintering aid; and 3 using nanometer size Sb3+ doped powders with sintering aids. Grain size effect on PTCR characteristics is investigated through comparison between micrometer size powder sintered pellets and nanometer size powder sintered pellets. The former has lower resistivity at temperatures below the Curie temperature (Tc) and high resistivity at temperatures above the Curie temperature (Tc) along with higher ñmax/ñmin ratio (ñmax is the highest resistivity at temperatures above Tc, ñmin is the lowest resistivity at temperatures below Tc), whereas the latter has both higher ñmax and ñmin. Also, ñmax/ñmin is smaller than that of pellets with larger grain size. The reason is that the solid with small grain size has more grain boundaries than the solid with large grain size. The contribution z at room temperature and high temperature and a lower ñmax/ñmin ratio value.

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Organic electronic devices such as organic field effect transistors (OFETs), light- emitting diodes (OLEDs), resistive memory elements or organic solar cells have attracted an increasing attention in recent years due to the vision of a low-cost and large-scale production of printable electronics. Many papers published during the last decade focused on the intrinsic properties of organic conductors, semiconductors and dielectric materials. Since most of the devices consist of multilayer structures the mutual influence of the processes that take place in the particular layers are important for the functionality of the whole device. This work is aimed to contribute to the characterization and understanding of the mutual interactions of individual layers in the multilayer structures of organic devices. The main achievements of this work can be listed as: (i) Optimization of the thermal stability and dielectric properties of cyanoethylated polyvinylalcohol (CEPVA) high-k dielectric by the crosslinking reaction with the low molecular weight materials or mixing with a high Tg polymer. (ii) Finding possible phenomena in the CEPVA polymer dielectric that influence the charge carrier transport in the OFET active channel made of bis(triisopropylsilylethynyl) pentacene organic semiconductor, using a...