Abstract: Provided is a light-emitting quantum dot coated with at least one blue-light absorption layer, including an alloy type core consisting of Cd, Se, Zn, and S, a first shell layer having a zinc blende structure and being coated on the surface of the alloy core, and at least one second shell layer having a wurtzite structure and being coated on a surface of the first shell layer, wherein the element ratio of each of Zn and S accounts for 30 to 50% of the overall core, and the content of Cd and Se gradually decreases outward from the core center. Also provided is a method for preparing the core-shell type light-emitting quantum dot. By having the alloy core, the first shell layer with a zinc blende structure, and the second shell layer with a wurtzite structure, the core-shell type quantum dot can achieve quantum efficiency of more than 95% and have high-temperature resistance and excellent water- and oxygen-barrier performance.

Abstract: Provided is a core-shell type light-emitting quantum dot, including an alloy type core consisting of Cd, Se, Zn, and S, and a shell layer having a zinc blende structure and being coated on the surface of the alloy core, wherein the element ratio of each of Zn and S accounts for 30 to 50% of the overall core, and the content of Cd and Se gradually decreases outward from the core center. Also provided is a method for preparing the core-shell type light-emitting quantum dot. By having the alloy core and the shell layer with a zinc blende structure, the core-shell type quantum dot can achieve quantum efficiency of 95%, and have high temperature resistance and excellent water- and oxygen-barrier performance.