  A two-dimensional (2D) ZnS photonic crystal was deposited on the surface of a
one-dimensional (1D) III-nitride micro cavity light-emitting diode (LED), to
intermix the light extraction features of both structures (1D+2D). The
deposition of an ideal micro-cavity optical thickness of lambda/2 is
impractical for III-nitride LEDs, and in realistic multi-mode devices a large
fraction of the light is lost to internal refraction as guided light.
Therefore, a 2D photonic crystal on the surface of the LED was used to diffract
and thus redirect this guided light out of the semiconductor over several
hundred microns. Additionally, the employment of a post-epitaxy ZnS 2D photonic
crystal avoided the typical etching into the GaN:Mg contact layer, a procedure
which can cause damage to the near surface.
