Abstract: The specification describes thin film transistor integrated circuits wherein the TFT devices are field effect transistors with inverted structures. The interconnect levels are produced prior to the formation of the transistors. This structure leads to added flexibility in processing. The inverted structure is a result of removing the constraints in traditional semiconductor field effect device manufacture that are imposed by the necessity of starting the device fabrication with the single crystal semiconductor active material. In the inverted structure the active material, preferably an organic semiconductor, is formed last in the fabrication sequence. In a preferred embodiment the inverted TFT devices are formed on a flexible printed circuit substrate.

Abstract: The specification describes thin film transistor integrated circuits wherein the TFT devices are field effect transistors with inverted structures. The interconnect levels are produced prior to the formation of the transistors. This structure leads to added flexibility in processing. The inverted structure is a result of removing the constraints in traditional semiconductor field effect device manufacture that are imposed by the necessity of starting the device fabrication with the single crystal semiconductor active material. In the inverted structure the active material, preferably an organic semiconductor, is formed last in the fabrication sequence.

Abstract: A process for fabricating an integrated circuit device is disclosed. The integrated circuit has a plurality of TFTs and an electrical interconnect structure. In the process, at least some constituents of the TFTs are formed on a first substrate. At least the interconnect structure is formed on a second substrate. The two substrates are laminated together to form the integrated circuit device having fully formed TFTs.

Abstract: A device in which one or more thin film transistors are monolithically integrated with a light emitting diode is disclosed. The thin film transistor has an organic semiconductor layer. The light emitting layer of the light emitting diode is also an organic material. The device is fabricated economically by integrating the fabrication of the thin film transistor and the light emitting diode on the substrate and by employing low cost fabrication techniques.

Abstract: The specification describes source/drain contact material that is compatible with organic semiconductors in thin film transistor integrated circuits. The contact material is nickel/gold wherein the nickel is plated as Ni--P on a base conductor, preferably TiN.sub.x, by electroless plating, and the gold overlay is deposited by displacement plating. It was found, unexpectedly, that forming Ni/Au contacts in this way extends the lifetime of TFT devices substantially.

Abstract: A process for fabricating thin film transistors in which the active layer is an organic semiconducting material with a carrier mobility greater than 10.sup.-3 cm.sup.2 /Vs and a conductivity less than about 10.sup.-6 S/cm at 20.degree. C. is disclosed. The organic semiconducting material is a regioregular (3-alkylthiophene) polymer. The organic semiconducting films are formed by applying a solution of the regioregular polymer and a solvent over the substrate. The poly (3-alkylthiophene) films have a preferred orientation in which the thiophene chains has a planar stacking so the polymer backbone is generally parallel to the substrate surface.

Abstract: Optical modulators and switches for use in telecommunications systems are disclosed having solid-state crystalline optical material comprised of III-V, II-VI, and IV semiconductor nanocrystals embedded in a polymer matrix. In a preferred embodiment, the crystalline material comprises CdSe crystals sized at less than 5.8 nm in diameter and more preferably at less than about 4 nm in diameter and advantageously embedded in poly(vinyl pyridine). The crystalline material sandwiched between two electrodes defines an optical modulator. In one preferred embodiment, the crystalline material with ten-percent crystal embedded in a polymer will exhibit with an applied voltage of 100V, a differential absorbance spectra (.DELTA.A) of about 50 cm.sup.-1 at wavelengths of about 610 nm and a differential refractive index (.DELTA.n) of about 10.sup.-4 at wavelengths of about 625 nm.

Abstract: A class of blue emitting materials, that, when placed in EL devices with an emitter layer and a hole transporter layer, provide EL devices that emit white light. The blue-emitting material has a non-polymeric molecular structure that comprises a five or six-membered heterocyclic moiety selected from the groups consisting of oxazole, imidazole, quinoline and pyrazine with at least three substituents pendant thereto. The blue-emitting materials of the present invention have certain characteristics that allow them to be formed into films with advantageous properties. The films formed from these materials are amorphous (i.e they have a crystal size less than about 1000 .ANG.). The thickness of the films of the blue-emitting material is less than 600 .ANG. in the devices of the present invention.

Abstract: An organic laser according to the invention comprises an electrically pumped source of incoherent radiation with organic active region, and further comprises a waveguide structure that receives the incoherent radiation. The core of the waveguide comprises organic material that absorbs the incoherent radiation and emits coherent radiation of longer wavelength. The laser forms a unitary structure, with the source of incoherent radiation being close to the waveguide core, exemplarily less than 10.lambda. from the core, where .lambda. is the laser wavelength. Exemplarily the laser is embodied in a planar waveguide laser, in a microdisk laser, or in a laser comprising a photonic bandgap structure.

Abstract: Disclosed is a microcavity organic light emitter having reduced variation in emission spectra per change in viewing angle. In an illustrative embodiment, a microcavity EL device comprises a microcavity layer structure stacked on a symmetric, non-planar surface of a substrate. The microcavity layer structure includes at least a first reflective layer on the non-planar substrate surface, a second reflective layer and an active layer having organic material capable of electroluminescence between the first and second reflective layers. The non-planar surface may be a shallow cone, frustum, a dome-like surface, or a combination thereof.

Abstract: Optical microcavities are potentially useful as light emitters for, e.g., flat panel displays. Such microcavities comprise a layer structure, including two spaced apart reflectors that define the cavity, with a layer or layers of organic (electroluminescent) material disposed between the reflectors. We have discovered that a microcavity can simultaneously emit radiation of two or more predetermined colors such that the emission has a desired apparent color, exemplarily white. Emission of two or more colors requires that the effective optical length of the cavity is selected such that the cavity is a multimode cavity, with the wavelengths of two or more of the standing wave modes that are supported by the cavity lying within the emission region of the electroluminescence spectrum of the active material. A particular embodiment with two organic emitting (active) layers is disclosed.

Abstract: Complementary circuits with inorganic n-channel thin film transistors (TFTs) and organic p-channel TFTs can exhibit advantageous properties, without being subject to some of the drawbacks of prior art complimentary inorganic TFTs or complementary organic TFTs. In preferred embodiments of the invention, the n-channel inorganic TFTs have an amorphous Si active layer, and the p-channel organic TFTs have .DELTA.-hexathienylene (.alpha.-6T) active layer. Complementary inverters according to the invention are disclosed, as is an exemplary processing sequence that can be used to manufacture integrated complementary inverters and other complementary circuits according to the invention.

Abstract: Articles according to the invention comprise an improved organic thin film transistor (TFT) that can have substantially higher source/drain current on/off ratio than conventional organic TFTs. An exemplary TFT according to the invention comprises, in addition to a p-type first organic material layer (e.g., .alpha.-6T), an n-type second organic material layer (e.g., Alq) in contact with the first material layer. TFTs according to the invention can be advantageously used in, for instance, active liquid crystal displays and electronic memories.

Abstract: Organic thin film transistors having improved properties (e.g., on/off ratio>10.sup.5 at 20.degree. C.) are disclosed. The improved transistors comprise an organic active layer of low conductivity (<5.times.10.sup.-8 S/cm at 20.degree. C., preferably less than 10.sup.-8 or even 10.sup.-9 S/cm). A method of producing such materials is disclosed. Rapid thermal annealing was found to have beneficial results. An exemplary and preferred material is .alpha.-hexathienylene (.alpha.-6T). The improved transistors are expected to find use for, e.g., active liquid crystal displays and for memories.

Abstract: Optical microcavities are potentially useful as light emitters for, e.g., flat panel displays. Such microcavities comprise a layer structure, including two spaced apart reflectors that define the cavity, with a layer of organic (electroluminescent) material disposed between the reflectors. We have discovered that a microcavity can simultaneously emit radiation of two or more predetermined colors such that the emission has a desired apparent color, exemplarily white. Emission of two or more colors requires that the effective optical length of the cavity is selected such that the cavity is a multimode cavity, with the wavelengths of two or more of the standing wave modes that are supported by the cavity lying within the emission region of the electroluminescence spectrum of the active material.

Abstract: Apparatus according to the invention comprises at least two optical microcavity light emitters. Each one of the at least two light emitters comprises spaced apart reflectors that define a microcavity, and further comprises organic material that is capable of electro-luminescence (e.g., tris (8-hydroxyquinolinol) aluminum, commonly referred to as "Alq"), and means for applying an electric field across the organic material. One of the at least two microcavities has effective optical length L.sub.1, and the other microcavity has effective optical length L.sub.2 .noteq.L.sub.1, with the optical lengths selected such that one of the microcavities emits radiation of a first color (e.g., red), and the other microcavity emits radiation of a second color (e.g., green). In many cases there will be present also a third microcavity that emits radiation of a third color (e.g., blue).