A display device includes: a display substrate; a light amount control layer on the display substrate; a first polarizer on the light amount control layer; and a color conversion layer on the first polarizer. The color conversion layer includes a phosphor, the phosphor includes a quantum dot, the quantum dot including: a core; a first shell surrounding the core; and a second shell surrounding the first shell, and the quantum dot has a diameter ranging from about 2 nm to about 32 nm.