Abstract: A zinc oxide semiconductor has a zinc oxide-based laminated structure including two layers of a zinc oxide layer with a lattice volume of Va and a donor concentration of Na, and a zinc oxide or zinc oxide solid solution layer with a lattice volume of Vb and a donor concentration of Nb. The relationships of Va<Vb and Na>Nb are satisfied. The layer with the lattice volume Va serves as a charge-supplying layer and the layer with the lattice volume Vb serves as a charge-receiving layer in the laminated structure. The charge is transferred from the layer serving as the charge-supplying layer to the layer serving as the charge-receiving layer even when no external electric field is applied to the laminated structure. A charge depletion layer is formed in the charge-supplying layer due to charge transfer from the charge-supplying layer to the charge-receiving layer.

Abstract: The present invention relates to a zinc oxide phosphor characterized by emitting visible light with a broad emission spectrum close to white, and a process for producing the same. A powder prepared by adding a plurality of additives to zinc oxide and heat-treating the resulting mixture is further hydrogenated to improve the luminous efficiency of the zinc oxide phosphor. The zinc oxide phosphor providing a broad emission spectrum covering a wavelength range over substantially the entire visible region can be applied to a white diode, a white vacuum fluorescent display, and a fluorescent paint.

Abstract: Disclosed are a zinc oxide resistor structure, and methods of forming a glass layer and a resistor, which are required for producing the resistor structure. The zinc oxide resistor comprises zinc oxide grains and an oxide glass layer which contains bismuth and boron and intervenes between the zinc oxide grains. The oxide glass layer residing between the zinc oxide grains changes the electric properties between the grains to achieve a higher resistance and a non-ohmic characteristic of a voltage-dependent resistance value in the resistor. This non-ohmic characteristic can be applied, particularly, to a non-ohmic device to be compatible with a low-voltage operation. Differently from conventional resistors, the oxide glass layer intervening between the zinc oxide grains can achieve an enhanced mechanical strength of a junction in the device.

Abstract: The present invention relates to a zinc oxide phosphor characterized by emitting visible light with a broad emission spectrum close to white, and a process for producing the same. A powder prepared by adding a plurality of additives to zinc oxide and heat-treating the resulting mixture is further hydrogenated to improve the luminous efficiency of the zinc oxide phosphor. The zinc oxide phosphor providing a broad emission spectrum covering a wavelength range over substantially the entire visible region can be applied to a white diode, a white vacuum fluorescent display, and a fluorescent paint.

Abstract: The present invention is effective for causing charge separation by complexing zinc oxide crystals in different states one another when a zinc oxide semiconductor is used as an electronic element. The present invention provides a zinc oxide-based laminated structure comprising two layers of a zinc oxide or zinc oxide solid solution layer with a lattice volume of Va and a donor concentration of Na, and a zinc oxide or zinc oxide solid solution layer with a lattice volume of Vb and a donor concentration of Nb, wherein the relationships of Va<Vb and Na>Nb being satisfied between both layers of the laminated structures; and the layer with the lattice volume Va serves as a charge-supplying layer and the layer with the lattice volume Vb serves as a charge-receiving layer in the laminated structure.

Abstract: Disclosed are a zinc oxide resistor structure, and methods of forming a glass layer and a resistor, which are required for producing the resistor structure. The zinc oxide resistor comprises zinc oxide grains and an oxide glass layer which contains bismuth and boron and intervenes between the zinc oxide grains. The oxide glass layer residing between the zinc oxide grains changes the electric properties between the grains to achieve a higher resistance and a non-ohmic characteristic of a voltage-dependent resistance value in the resistor. This non-ohmic characteristic can be applied, particularly, to a non-ohmic device to be compatible with a low-voltage operation. Differently from conventional resistors, the oxide glass layer intervening between the zinc oxide grains can achieve an enhanced mechanical strength of a junction in the device.

Abstract: A process for producing a powder material of perovskite or its solid solution represented by the formula:ABO.sub.3wherein A is one or more metal elements coordinated with 12 oxygen atoms, and B is one or more metal elements coordinated with 6 oxygen atoms, which comprises contacting an aqueous or alcohol solution of either component A or component B with a precipitating solution to form precipitates, then adding an aqueous or alcohol solution of the other component to form precipitates, and drying the precipitates, followed by calcining at a temperature of from 400.degree. to 1200.degree. C.