An light emitting diode includes an insulating substrate, a P-type semiconductor layer, a semiconductor carbon nanotube layer, an MgO layer, a functional dielectric layer, and a first electrode, and a second electrode. The P-type semiconductor layer is located on the insulating substrate. The semiconductor carbon nanotube layer is located on the P-type semiconductor layer. The MgO layer is located on the semiconductor carbon nanotube layer. The functional dielectric layer covers the MgO layer. The first electrode is electrically connected to the P-type semiconductor layer. The second electrode is electrically connected to the semiconductor carbon nanotube layer.