The invention discloses a core-shell
quantum dot, a preparation method thereof and a
quantum dot photoelectric device. The preparation method of the core-shell
quantum dot includes the following steps: S1, adding a
quantum dot core to a solution comprising first
cadmium precursors and first
zinc precursors to form a first
mixed solution; S2, adding first anion precursors to the first
mixed solution, and
coating the
quantum dot core with a middle shell layer; S3, adding a purified core-shell
quantum dot to a solution comprising second
zinc precursors to obtain a second
mixed solution; S4, adding second anion precursors to the second mixed solution for reaction, and
coating the core-shell quantum dot with an outer shell layer. The preparation method is further characterized by at least one of A, B and C: A, in the step S2, after the first anion precursors are added, a first certain amount of second
cadmium precursors are added for reaction; B, a step S3' is included between the step S3 and the step S4, and a second certain amount of third
cadmium precursors are added to the second mixed solution; C, in the step S4, a third certain amount of the third cadmium precursors are added to the second mixed solution for reaction.