Patent ID: 8779456

Claim:
A light emitting device having plasmonically enhanced emission, comprising: an inverted light emitting diode (LED) having a plasmonic metal coating thereon, the inverted LED comprising: an n-type substrate contacted to a first n-type electrode configured to provide an Ohmic contact to the n-type substrate; an n-type cap layer disposed on the n-type substrate; a tunnel junction disposed on the n-type cap layer, the tunnel junction comprising a highly doped n-type layer disposed on the n-type cap layer and a highly doped p-type layer disposed on the highly doped n-type layer, the tunnel junction being configured to allow a non-rectified current to flow from the n-type substrate into the n-type cap layer; and an active quantum well region disposed between a p-type layer on a bottom side thereof adjacent the p-type layer of the tunnel junction and an n-type contact layer on a top side thereof, the n-type contact layer having a plasmonic metal coating comprising a plurality of metal nanoparticles disposed on a first discrete region of the n-type contact layer, the n-type contact layer also having a second n-type electrode disposed on a second discrete region of the n-type contact layer, the second n-type electrode being contacted to the n-type contact layer to provide an Ohmic contact to the n-type contact layer, and the plasmonic metal coating and the second n-type electrode forming separate and discrete structures on the n-type contact layer; wherein the plasmonic metal coating is configured to match a plasmonic response to a peak emission from the active quantum well region and to generate a plurality of surface plasmons at an interface of the plasmonic metal coating and the n-type contact layer, the n-type contact layer being sufficiently thin to cause the active quantum well region to be within a fringing field of the surface plasmons; wherein electrons from the n-type contact layer and holes from p-type layer form electron-hole pairs in the active quantum well region upon the application of current to the inverted LED via the first and second n-type Ohmic contacts; wherein a first plurality of the electron-hole pairs decay via a first decay route to produce a first light emission from the light-emitting device; and wherein the second plurality of the electron-hole pairs couple with a corresponding plurality of the surface plasmons and decay via a second decay route provided by the coupling of the electron-hole pairs and the surface plasmons to produce a second light emission from the light-emitting device; the first and second light emissions providing an enhanced light emission from the light-emitting device.