A display device is provided. The display device includes a substrate, a first transistor, and a light emitting diode. The first transistor is disposed on the substrate, wherein the first transistor comprises a first semiconductor layer comprising silicon having a first lattice constant. The light emitting diode is disposed on the substrate and electrically connected to the first transistor, wherein the light emitting diode comprises a semiconductor layer comprising gallium nitride having a second lattice constant and a third lattice constant, and the third lattice constant is greater than the second lattice constant. A ratio of the second lattice constant to the first lattice constant is greater than or equal to 0.56 and is less than or equal to 0.68.