The first solid-state field-effect transistor has been fabricated utilizing a film of an organic macromolecule, polythiophene, as a semiconductor. The device characteristics have been optimized by controlling the doping levels of the polymer. The device is a normally off type and the source (drain) current can be modulated by a factor of 102–103 by varying the gate voltage. The carrier mobility and the transconductance have also been determined to be ∼10−5 cm2/V s and 3 nS, respectively, by means of electrical measurements.

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synopsisPolyimide precursors were synthesized from a diamine and a diacid chloride that was derived from the reactant with promellitic dianhydride and 0-nitrobenzyl alcohol. Their thermal properties were studied in nitrogen using dynamic thermogravimetry, and the photoreaction mechanism was investigated by ultraviolet and infrared spectrophotometry. The polyimide precursors were spin-coated onto silicon wafers, prebaked, and then exposed to W light from a high pressure Hg-Xe lamp. When the f i l m s were dipped into 2% aqueous KOH after irradiation, the expased area dissolved forming high resolution Patterns. Relative sensitivities of the polymers were determined.

The temperature dependence of the J-V characteristics of an In/poly(N-methylpyrrole) junction device has been measured in order to investigate the junction properties. The barrier height and the effective Richardson constant of the junction have been determined to be 0.38 eV and 1.3*10-4 A cm-2 K-1 by the Richardson plots. The extremely small effective Richardson constant has been due to the existence of the composite layer, acting as a tunnelling one, formed by the reaction of the indium with the polymer surface.

A thin film of poly(N-methylpyrrole) has been prepared by a chemical method. The chemical structure of the polymer resembles that of the electrochemically prepared one. A fild-effect transistor has been fabricated utilizing the polymer as a semiconducting material.

Polyquinazolones containing 4‐substituted phenyl groups (H, Cl, CH3, CH3O, NO2) on the quinazolone ring were synthesized in m‐cresol and their thermal properties were studied by using dynamic thermogravimetry and isothermal weight loss in nitrogen and air. Polyquinazolones were synthesized with intrinsic viscosities in the range of 0.2–0.7 dL/g when phosphorus pentoxide was used as a catalyst. In TGA studies, there was a difference in the initial decomposition temperature of polyquinazolones with varying substituted groups. The introduction of substituted groups reduced oxidative thermal stability of the polymers. Furthermore, the thermal degradation mechanism was investigated by infrared spectrophotometry.

The monomers were derived from pyromellitic dianhydride and a42-nitrophenyl)ethanol, which was prepared by selective reduction of 2-nitroacetophenone. Polyimide precursors were synthesized by an interfacial polycondensation technique. Their thermal properties in nitrogen were studied by dynamic thermogravimetry. The photorearrangement of 2-nitrobenzyl ester having a methyl group at the aposition compared to that of the unsubstituted ester was investigated by infrared spectrophotometry. The polymers obtained in this study gave a high proportion of photorearrangement to show high sensitivity. The exposed areas dissolved in 2% aqueous KOH, forming high resolution patterns because they did not swell during the developing process.