Abstract: The present invention provides a multi UV-LED probe system for detection of a characteristic of a sample, the system including a device comprising a probe head, the probe head including a plurality of UV-LEDs, an optic fiber bundle, an optional heating surface, an optional cooling surface and a light directing means adapted to transfer UV from the plurality of UV-LEDs to a region of the sample and further adapted to receive fluorescent light from the region to focus it into the optic fiber bundle and a power source adapted to provide electrical energy to the plurality of UV-LEDs, a spectrophotometer configured to receive the fluorescent light from the optic fiber bundle and a processor adapted to receive signals associated with the fluorescent light and to process the signals to provide the detection of the characteristic of the sample.

Abstract: The present invention provides a multi UV-LED probe system for detection of a characteristic of a sample, the system including a device comprising a probe head, the probe head including a plurality of UV-LEDs, an optic fiber bundle, an optional heating surface, an optional cooling surface and a light directing means adapted to transfer UV from the plurality of UV-LEDs to a region of the sample and further adapted to receive fluorescent light from the region to focus it into the optic fiber bundle and a power source adapted to provide electrical energy to the plurality of UV-LEDs, a spectrophotometer configured to receive the fluorescent light from the optic fiber bundle and a processor adapted to receive signals associated with the fluorescent light and to process the signals to provide the detection of the characteristic of the sample.

Abstract: A phosphor layer for an electroluminescent panel comprises a phosphor powder held in a binder. The binder comprises a mixture of two constituents, one of which is a drying oil or a semi-drying oil or a derivative and the other constituent is a sol-gel precursors. Examples of suitable oils are linseed oil, grape seed oil, sunflower oil and soybean oil. Examples of suitable sol-gel precursors are tetraethyl orthosilicate, boron iso-propoxide, aluminium sec-butoxide titanium iso-propoxide. Metal salts such as metal alkoxides, metal acetates and metal nitrates may be mixed with the sol-gel precursors.

Abstract: A phosphor layer for an electroluminescent panel comprises a phosphor powder held in a binder. The binder comprises a mixture of two constituents, one of which is a drying oil or a semi-drying oil or a derivative and the other constituent is a sol-gel precursers. Examples of suitable oils are linseed oil, rape seed oil, sunflower oil and soyabean oil. Examples of suitable sol-gel precursers are tetraethyl orthosilicate, boron iso-propoxide, aluminium sec-butoxide and titanium iso-propoxide. Metal salts such as metal alkoxides, metal acetates and metal nitrates may be mixed with the sol-gel precursers.

Abstract: A phosphor layer for an electroluminescent panel comprises a phosphor powder held in a binder. The binder comprises a mixture of two constituents, one of which is a drying oil or a semi-drying oil or a derivative and the other constituent is a sol-gel precursers. Examples of suitable oils are linseed oil, rape seed oil, sunflower oil and soyabean oil. Examples of suitable sol-gel precursers are methyl orthosilicate, boron iso-propoxide, aluminium sec-butoxide and titanium iso-propoxide. Metal salts such as metal alkoxides, metal acetates and metal nitrates may be mixed with the sol-gel precursers.

Abstract: Sulphides are prepared by combining a dithionite compound with an aqueous alkaline solution of an appropriate cation or mixture of cations. On heating the corresponding sulphides are precipitated. The dithionite compound may be a dithionite dianion which is produced as an intermediary when thiourea dioxide is used as a starting material in the solution. Examples of appropriate cations are zinc (as zinc acetate) and copper (as copper acetate). The precipitate is dried and subsequently fired to produce high quality sulphides which may be used as phosphors or other optoelectronic materials.

Abstract: Sulphides are prepared by combining a dithionite compound with an aqueous alkaline solution of an appropriate cation or mixture of cations. On heating the corresponding sulphides are precipitated. The dithionite compound may be a dithionite dianion which is produced as an intermediary when thiourea dioxide is used as a starting material in the solution. Examples of appropriate cations are zinc (as zinc acetate) and copper (as copper acetate). The precipitate is dried and subsequently fired to produce high quality sulphides which may be used as phosphors or other optoelectronic materials.

Abstract: Sulphides and selenides are prepared by dissolving sulphur or selenium in an aqueous or non-aqueous solution of hydrazine hydrate. The solution is combined with a solution of an appropriate cation to precipitate the corresponding sulphide or selenide. Solutions of two or more cations may be used to produce ternary compounds of sulphur and selenium, for example thio-gallates. Likewise both sulphur and selenium can be used together to produce sulpho-selenides. The method is particularly applicable to the production of doped phosphors by the inclusion of solutions containing the appropriate dopant.

Abstract: A d.c. or a.c. electroluminescent panel comprises a transparent substrate, a transparent first electrode film, a thin film phosphor layer, a black or dark powder back layer of electrically conductive material, and a second electrode film. Application of a voltage across the phosphor layer causes it to emit light. In this invention, the black powder back-layer significantly enhances the contrast of the panel.

Abstract: This invention provides phosphors for use in electroluminescent devices. Each phosphor contains a dopant, selected from the group consisting of europium, erbium, and terbium and at least one of the sulphides selected from the group consisting of strontium and calcium sulphide.

Abstract: This invention provides phosphors for use in electroluminescent devices. Each phosphor contains a dopant and at least one of the sulphides of the group consisting of strontium, calcium, barium and magnesium sulphide.

Abstract: In an electroluminescent device comprising a layer of electroluminescent material disposed between a pair of electrodes, and a transparent substrate, the electrode between the substrate and the layer of electroluminescent material is transparent and has a surface portion remote from the substrate having properties substantially confining current flow therethrough to discrete regions thereof. In one form the transparent electrode has a first layer adjacent the substrate of electrically-conductive material and a second layer of semiconducting or insulating material. In another form of the transparent electrode this electrode is of a metal oxide and the discrete regions are in a substantially pure form of that metal.