▎ 摘　　要

NOVELTY - A blue light perovskite nano-crystal doped with copper ions comprises cesium, lead, copper and bromine. USE - Blue light perovskite nano-crystal doped with copper ions used in photoelectric conversion material applications. ADVANTAGE - The blue light perovskite nano-crystal doped with copper ions introduces divalent metal element copper ions with small ionic radius and strong bonding energy. The interaction of the cesium atom at the A site and bromine atom at the X site is enhanced, and the thermal stability of the perovskite is improved. DETAILED DESCRIPTION - A blue light perovskite nano-crystal doped with copper ions has composition of formula: CsPbxCu1-xBr3, where x is more than 0 and less than 1. INDEPENDENT CLAIMS are included for the following: 1. preparation of blue light perovskite nano-crystal doped with copper ions, which involves mixing copper bromide, lead bromide and octadecene ligand uniformly, adding cesium oleate solution, magnetically stirring for 5-10 seconds, injecting liquid nitrogen, and cooling; 2. application of amino functionalized graphene which is obtained by amino functionalized treatment for loading copper ion doped blue-light perovskite nanocrystals; and 3. graphene-loaded copper ion-doped blue-light perovskite nanocrystalline dispersion liquid, which comprises amino-functionalized graphene dispersion liquid and copper ion-doped blue-light perovskite nanocrystalline dispersion liquid.