Display device and manufacturing method thereof

An organic light emitting diode display device comprising:

• a base substrate;
• an organic light emitting diode on the base substrate;
• and
• a color conversion layer on the organic light emitting diode,
• wherein the color conversion layer comprises a phosphor,
• the phosphor comprises a quantum dot, the quantum dot comprising:
• a core;
• a first shell surrounding the core;
• and a second shell surrounding the first shell, wherein the first shell comprises at least one of:
• InP, CdSe, and ZnTe, and
• the quantum dot has a diameter ranging from about 2 nm to about 32 nm.