2results about How to "Small absorption coefficient" patented technology

This invention relates to the field of LED technology, and particularly to a high-efficiency violet LED epitaxial structure and its growth method. The epitaxial structure, from bottom to top, includes: a patterned AlGaN template substrate and a GaN-based epitaxial layer. The patterned AlGaN template substrate sequentially includes a growth substrate, a buffer layer, an AlGaN layer, and a mask layer, wherein the mask layer is a periodically patterned mask. The GaN-based epitaxial layer sequentially includes: an AlGaN capping layer, an n-type semiconductor layer, a stress relief layer, a multi-quantum-well active region, an electron blocking layer, and a p-type semiconductor layer. The n-type semiconductor includes an Alx3Ga1-x3N layer with an Al composition of 0.01 ≤ x3 ≤ 0.05 and x3 ≥ x2. This invention effectively blocks dislocation propagation and reduces defect density through the synergistic design of the patterned AlGaN template substrate and the laterally epitaxially grown AlGaN capping layer; and achieves progressive stress relief and light absorption suppression through the gradient increase of Al composition in each layer of the all-AlGaN-based structure.

The present invention discloses a functional decorative black film and a preparation method thereof. The functional decorative black film provided by the present invention comprises a back glue layer and a substrate layer, wherein the back glue layer is coated with an adhesive on one side of the substrate layer; the substrate layer comprises the following raw materials in parts by weight: 100 parts of PET resin, 2-3 parts of antioxidant, 0.5-2 parts of thermal stabilizer, 5-8 parts of modified polyacrylate, 0.1-1 parts of lubricant, 15-20 parts of modified silica, 2-4 parts of curing agent, and 3-5 parts of black toner. The functional decorative black film provided by the present invention, firstly, the addition of modified silica makes the film have a lower transmittance under visible light and a higher transmittance under near-infrared light; secondly, the modified polyacrylate improves the alkali resistance and water resistance of the film. Therefore, the black film provided by the present invention can be applied to military products, automotive radars, security, electronic consumer products, robots and drones to achieve invisibility under near-infrared.