Efficient enhanced specific rare earth photoluminescence anti-counterfeiting film and preparation method thereof

Abstract

The invention provides an efficient enhanced specific rare earth photoluminescence anti-counterfeiting film and a preparation method thereof. The anti-counterfeiting film comprises a heat insulation base layer, a plasmon enhancement layer, an optical isolation layer, a heat absorption type rare earth light-emitting layer and a heat insulation cover layer from bottom to top. The heat insulation base layer and the heat insulation cover layer are used for carrying out heat insulation and heat storage on photo-thermal induced by the plasmon enhancement layer, and the photo-thermal is absorbed by the heat absorption type rare earth light-emitting layer so as to assist the plasmon enhancement layer in improving rare earth light emission; the mobility of carriers and the excitation electric fieldor emission electric field of light-emitting particles are increased through the plasmon enhancement layer, so that rare earth luminescence is enhanced; energy is promoted to be transferred to the rare earth light-emitting layer through the optical isolation layer so as to optimize rare earth light emission. By means of the design, the heat absorption type rare earth light-emitting layer emits red, green and blue light after being subjected to stimulated radiation, the light-emitting enhancement effect that green light is stronger than blue light and red light can be achieved when absorbed heat is increased, and therefore, the specific anti-counterfeiting film high in safety, anti-counterfeiting identification degree and copying difficulty is obtained.

Description

technical field [0001] The invention belongs to the technical field of rare earth luminescent materials, and relates to a high-efficiency enhanced specific rare earth photoluminescent anti-counterfeiting film and a preparation method thereof. Background technique [0002] Commercial anti-counterfeiting occupies an indispensable and important position in the current economic and social development, ranging from small livelihood economy to enterprise production, national defense and military industry and other fields. With the development of display technology and the advancement of anti-counterfeiting technology, counterfeit and shoddy products have caused adverse effects on corporate reputation and social economy. Therefore, it is imminent to upgrade the production process of commercial anti-counterfeiting, thereby improving the technical difficulty, anti-counterfeiting specificity and recognizability. [0003] Rare earth luminescent materials have become one of the most wi...

AI Technical Summary

Problems solved by technology

However, there are the following problems that need to be solved urgently: (1) For endothermic rare earth luminescent materials, the photothermal heat induced by plasmons is not managed intensively, which not only makes the thermal energy loss in the form of thermal radiation but also It limits the enhancement of luminescence, and will burn and damage most products; (2) Surfactants, such as oleylamine, are used in the preparation process of most nanomaterials with plasmonic properties, which cause the carriers to be localized. (3) The plasmonic resonance peaks of noble metal-enhanced rare-earth luminescence with strong plasmonic properties need to be modulated to precisely match the excitation wavelength, while Plasmons of noble metals are sensitive to shape, size, and medium environment, which increases the difficulty of adjusting the plasmons of noble metals, and such as Au, Ag, etc. are expensive and have limited reserves on the earth; (4 ) In most of the researches that introduce plasmon-enhanced rare earth upconversion luminescence, although they have three-color photoluminescence, they have not realized the specific anti-counterfeiting identification that the luminescence gain of green light is much higher than that of blue light and red light.

For example, the invention patent CN107286924B discloses an upconversion nanocrystal material and its preparation method for infrared light-excited red, green and blue three-color orthogonal fluorescence emission. The transmission layer and the energy absorption layer are composed of five types of shell layers. Each energy absorption layer absorbs the energy of infrared excitation light of different wavelengths and transmits it to the luminescence center to realize the fluorescence emission of the three primary colors of red, green and blue. Sensitive green light is much higher than the luminous gain of blue light and red light for specific anti-counterfeiting identification

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