55results about How to "Wide range of excitation wavelengths" patented technology

The invention relates to a vanadate garnet type fluorescent material as well as a preparation method and the application thereof, belonging to the field of vanadate inorganic luminescent materials and aiming at solving the technical problem of providing a wideband-emission fluorescent material with wide excitation spectrum range and high luminescent strength. The vanadate garnet type fluorescent material comprises the components: A(2-2x)K(1+x)NxM2V3O12, wherein x is more than or equal to 0 and less than or equal to 0.1, A is selected from at least one of Ca, Sr and Ba, M is selected from at least one element of Mg and Zn, and N is selected from at least one element of Ce, Pr, Sm, Nd, Eu, Gd, Tb, Dy, Ho, Er, Tm and Bi. The fluorescent material belongs to a garnet-type structure in a cubic system and has high luminescent strength and wide excitation spectrum band, and an emission spectrum is emitted by a wideband for covering the whole visible light region. The invention can be widely used in systems of electron, information, traffic, energy sources and illumination and has more remarkable superiority in the application of fourth-generation solid luminescent devices excited by purple light or long-wave ultraviolet light emitted by purple light or ultraviolet light-emitting diodes.

The invention relates to red phosphor powder for an LED, having a general chemical composition formula of ALn1-xNb2O7: xEu3+, wherein A comprises one or more than two of Li, Na, K or Rb, Ln comprises one or two of Gd or Y, and x is not smaller than 0.10 and is not larger than 1.00. The preparation method of the red phosphor powder for the white LED comprises the following steps of: (1) weighting,grinding and evenly mixing the raw materials according to the mol ratio of the ALn1-xNb2O7: xEu3+; (2) putting a mixture in the step (1) in air atmosphere of a muffle furnace to roast at 1000-1600 DEG C for 3-15h; and (3) post-treating the roasted product obtained in the step (2). The phosphor powder of the invention can be effectively excited by near-ultraviolet light and blue light to emit red light, can be favorably matched with near-ultraviolet light and blue light LED chips, has stable physical and chemical properties, avoids reactions with oxygen, water, carbon dioxide, and the like in environment and resists heat without toxicity or pollution nuisance. The preparation method is simple and easy to operate for directly roasting in air and has favorable application prospects.

The invention discloses near-infrared fluorescent powder. A general chemical formula of the near-infrared fluorescent powder is Ca3Ga(1.95-2X)In2XCr0.05Ge4O14, wherein x is greater than or equal to 0 and is smaller than or equal to 0.975. The invention further discloses a preparation method of the near-infrared fluorescent powder. The preparation method comprises the following steps that a) oxides or carbonates containing the elements of Ca, Ga, In, Cr and Ge are weighed according to the mole ratio of all the elements in the general chemical formula of the fluorescent powder, namely, Ca3Ga(1.95-2X)In2XCr0.05Ge4O14, the oxides or the carbonates are mixed and ground to obtain a mixture, and in the general chemical formula, wherein x is greater than or equal to 0 and is smaller than or equal to 0.975; b) the mixture is heated to 1100 to 1300 DEG C for calcination for 3 to 4h, and a sintering body is obtained; and C) the sintering body is cooled down to room temperature and then fully ground to obtain the near-infrared fluorescent powder. The near-infrared fluorescent powder prepared through the preparation method is wide in excitation wavelength range, high in luminous intensity, and high in stability; and an adopted high-temperature solid-phase preparation method is simple in process, easy to operate and control, high in safety, short in preparation time and high in production efficiency, the production cost is greatly reduced compared with the prior art, and the near-infrared fluorescent powder and the preparation method thereof are suitable for large-scale industrial production, application and popularization.

The invention relates to core-surface gradient nitrogen oxide fluorescent powder and a preparation method thereof. The fluorescent powder has the chemical formula LxSiyOZN(2 / 3)X+(4 / 3)Y-(2 / 3)Z:wR / L'xSiyOZN(2 / 3)X+(4 / 3)Y-(2 / 3)Z:wR, wherein L is at least one of Ca and Sr, L' is at least one of Ca, Sr and Ba, and R is at least one of Eu and Ce; and X is more than or equal to 0.8 and less than or equal to 1.2, Y is more than or equal to 1.8 and less than or equal to 2.2, Z is more than or equal to 1.8 and less than or equal to 2.2, and w is more than or equal to 0.01 and less than or equal to 0.1. The preparation method comprises the following steps of: 1) mixing according to the chemical formula, adding a fluxing agent, grinding, and uniformly mixing to form two kinds of mixed materials; 2) performing high-temperature roasting on the mixed materials at reducing atmosphere; and 3) partially or totally coating the roasted product L'xSiyOZN(2 / 3)X+(4 / 3)Y-(2 / 3)Z:wR by a spraying or deposition mode on the surface of a treated roasted product LxSiyOZN(2 / 3)X+(4 / 3)Y-(2 / 3)Z:wR. The excitation and emission range of the fluorescent powder is wide and can be adjusted, the lighting effect is improved, the color gamut is widened, and the fluorescent powder can be effectively used for a white light-emitting diode (LED) with a high color rendering index.