Conjugated polymer field-effect transistors (FETs) basedon regioregular poly-3-hexylthiophene (P3HT) with high field-effect mobilities up to 0.05-0.1 cm2/Vs and high ON-OFF current ratios of 106 -l0s are demonstrated. The high mobilities axe caused by supramoleculax ordering induced by self-organisation in solution-processed P3HT films. High ON-OFF current ratios are achieved after chemical reduction of residual extrinsic dopants.A detailed analysis of the channellength dependence of FET characteristics is presented. Integrated devices with polymer FETs driving polymer LEDs have been fabricated as a first step towards integrated optoelectronic circuits based on solution-processed conjugated polymers. 1 Introduction Light-emitting diodes LEDs based on semiconducting conjugated polymers have reached a performance level comparable to that ofthe best inorganic LEDs and are now starting to meet strict requirements for technological applications in polymer LED displays [1]. Polymer FETs have potential applications in cheap logic circuits on plastic substrates for identification tags and smart cards [2] or as driver electronics in active-matrixpolymer LED displays [3][4]. However, for transistor applications of conjugated polymers two main difficulties have to be overcome. The disordered, amorphous morphology of most solution-processed polymers typically results in low charge carrier mobilities < 10-3cm2/Vs [5].Polymers are also difficult to purify and residual extrinsic doping often results in high film conductivities limiting the transistor ON-OFF current ratio to typically < 103 -104. In the last two years significant progress with polymer FETs has been initiated by the demonstration of regioregular poly-5-hexylthiophene (P3HT) FETs with high field-effect mobilities of 1 -5 • 10-2cm2/Vs, although still relatively low ON-OFF current ratio of < 104 [6]. Here we report improvements of the device performance and the understanding of device characteristics that have enabled the study of fundamental electrical transport properties in

The feasibility of LiMgPO4 (LMP) ceramic for low‐temperature cofired ceramic (LTCC) application was investigated. The ceramic was prepared by the conventional solid‐state ceramic method. The ceramic sintered at 950°C showed a relative permittivity (ɛr) of 6.6 and high quality factor (Qu×f) of 79 100 GHz with a τf of −55 ppm/°C. The relatively large negative τf value was lowered by preparing LMP–TiO2 composite. The composite with 0.12 volume fraction TiO2 showed good microwave dielectric properties: ɛr=10, Qu×f=26 900 GHz, and τf=+1.2 ppm/°C. LMP–TiO2 composite did not react with the commonly used electrode material silver.

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Mechanically flexible butyl rubber–SrTiO3 composites were prepared through sigma mixing followed by hot pressing. Tensile tests established the mechanical flexibility of the composites. Swelling tests revealed the degree of matrix–filler interactions. The effect of SrTiO3 ceramic filler on the dielectric properties of the composites was studied at 1 MHz and 5 GHz using an LCR meter and a Split Post Dielectric Resonator, respectively. The relative permittivity of the composites increased with filler loading while maintaining low dielectric loss. For the maximum filler content of 0.42 volume fraction, the composite showed a relative permittivity of 13.2 and a loss tangent of 2.8 × 10−3 at 5 GHz. Theoretical modeling of effective relative permittivity of the composites was performed and the results were correlated with the experimental data. Effect of repeated bending on the microwave dielectric properties of the composite was also studied. The coefficient of thermal expansion of the composites was observed to decrease with the increased ceramic filler dispersion and reached a minimum value of 26.2 ppm/°C.