LIGHT-EMITTING DIODE WITH LOCAL PHOTONIC CRYSTALS

摘要

The light-emitting diode includes first and second layers of semiconductor material, having opposite conductivity types, an active light-emitting area located between the first and second layers of semiconductor material, an electrode arranged on the first layer of semiconductor material and a photonic crystal formed in the first layer of semiconductor material. The photonic crystal and the electrode are separated by a distance optimized to simultaneously promote the electric injection and minimize the light absorption in the LED.

主权项

1. Light-emitting diode comprising:
a first layer of a doped semiconductor material of a first conductivity type; a second layer of a doped semiconductor material of a second opposite conductivity type; an active light-emitting area located between the first and second layers of semiconductor material; an electrode arranged on the first layer of semiconductor material; and a photonic crystal formed in the first layer of semiconductor material; wherein the photonic crystal and the electrode are separated by a distance L verifying, to within 10%, the following equation:L=LSαLS-1ln(ηB-ηA)αLSηB-ηAαLS wherein: LS is the distance, from the electrode, at which the current density in the active light-emitting area is equal to the current density under the electrode divided by e; α is the absorption coefficient of the light modes propagating in the first and second layers of semiconductor material and in the active light-emitting area; ηA is the light extraction coefficient in a portion of the first and second layers of semiconductor material and of the active light-emitting area, located between the electrode and the photonic crystal; and ηB is the light extraction coefficient in the area of the photonic crystal.