U.S. Philips Corporation

Other

U.S. Phillips Corporation

Edsko E Havinga

Dagobert Michel De Leeuw

Wolter Ten Hoeve

Hans Wijnberg

Adam R Brown

Egbert Willem Meijer

Anita Pomp

Gerardus L Rikken

Knut H Chmii

Adam Richard Brown

Ton Rene Vries

Colin P Jarrett

Knut H Chmil

Sjef Nijhuis

Kornelis L Pouwer

Erik J Lous

Klaus A Mullen

The invention relates to a write-once read-many memory element (1), or an assembly thereof, which comprises a substrate on which electrodes are provided and between which a layer is sandwiched, which memory element includes a conjugated polymer or oligomer as well as a dopant. This memory element can be written by temporarily applying a sufficiently high voltage to the electrodes so that the electroconductivity of the layer is permanently reduced.

Write-once read-many electrical memory element of a conjugated polymer or oligomer

The invention relates to a method of preparing thiophene-containing or furan-containing conjugated compounds such as polythiophene. The method uses a precursor compound having tetrahydrothiophene or tetrahydrofuran precursor units having arylthio or alkylthio substituents. The precursor units can be thermally converted into thiophene or furan units. Due to the presence of the precursor units the precursor compound is soluble and can, unlike the corresponding conjugated compound, be processed from solution.

Method of preparing a thiophene-containing or furan-containing conjugated compound and precursor compound and use thereof for making semiconductor device

Method of preparing a thiophene-containing or furan-containing

The invention relates to a semiconducting polymer and a method of preparing a semiconducting polymer. The polymer in accordance with the invention has the repeating unit (--A--NH--B--S--), wherein A and B are conjugated groups. The polymer proves to be readily soluble already in customary organic solvents, without the groups A and B having been provided with saturated substituents, and, after doping, has an electric conductivity of approximately 1 S/cm. The method yields semiconducting polymers in accordance with the invention, which have a high molecular weight and few topological defects.

Semiconductor polymer

A semiconductor device is provided with an organic material which is formed by a solid-state mixture of organic donor and organic acceptor molecules. A semiconducting solid-state mixture is known with molar ratios between donor and acceptor molecules of 1.3:2 and 1.66:2. The known solid-state mixture has the disadvantage that its electrical conductivity is comparatively high, so that it is not possible to manufacture switchable devices from the mixture. Here the material includes an n- or p-type semiconductor material, the n-type semiconductor material having a molar ratio between the donor and acceptor molecules below 0.05, and the p-type semiconductor material having this ratio above 20. These solid-state mixtures may be used for manufacturing switchable semiconductor devices. The n- and p-type organic solid-state mixtures can be used for manufacturing transistors, diodes, and field effect transistors in a same manner as, for example, doped silicon or germanium.

Semiconductor device having an organic semiconductor material

Polycondensation of, for example, squaric acid with a benzodihydropyrrole, benzodithiazole, neocuproine, terthienyl or an aromatic diamine gives a semiconductive alternating copolymer having a small band gap. It is alternatively possible to use croconic acid or 5,6-dihydroxy-5-cyclohexene-1,2,3,4-tetraone instead of squaric acid. An alternating copolymer of croconic acid and a methyl-substituted benzodithiazole has the following repetititve unit: ##STR1##

Electrically conductive alternating copolymer and method of preparing

The polymers are prepared by using the new intermediate product which forms a polymeric precursor, and which is converted into the desired heterocyclic polymer by ring closure.

Method of manufacturing conductive heterocyclic polymers by reacting new

Nonlinear optical compound, nonlinear optical medium, method of manufacturing a nonlinear optical medium and device for doubling the frequency of a light wave. The invention relates to a nonlinear optical medium and a device comprising such a nonlinear optical medium which can be suitably used to double the frequency of red light, while forming blue light. The nonlinear optical medium comprises a polymer matrix and nonlinear optical compounds which contain a substituted sulphone group as the electron-acceptor group.

Device for doubling the frequency of a light wave comprising a

The invention relates to an arrangement for and a method of doubling the frequency of a light wave, for example to convert infrared light originating from a laser into green light. To that end a fundamental light wave is circularly polarized and passed through a non-linear optical medium, a second harmonic wave then being formed. The non-linear optical medium is formed from a centrosymmetrical material, whose molecules or molecular groups evidence chirality.

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Eindhoven, Netherlands

Edsko E Havinga