Abstract: An organic light emitting diode (OLED) includes a substrate, a first electrode layer, an organic emitting layer, a second electrode layer, and an electron injection layer, in which the electron injection layer is selected from an electron injection layer made from organic molecules, an electron injection layer with nano-grade thickness, or an electron injection layer having dipole moment organic molecules with nano-grade thickness. By utilizing the conformation of the electron injection layer, an OLED having stable operation can be achieved.