Semiconductor Light Emitting Device Configured To Emit Multiple Wavelengths Of Light

Abstract

In accordance with embodiments of the invention, a III-nitride structure includes a plurality of posts of semiconductor material corresponding to openings in a mask layer. Each post includes a light emitting layer. Each light emitting layer is disposed between an n-type region and a p-type region. A first light emitting layer disposed in a first post is configured to emit light at a different wavelength than a second light emitting layer disposed in a second post. In some embodiments, the wavelength emitted by each light emitting layer is controlled by controlling the diameter of the posts, such that a device that emits white light without phosphor conversion may be formed.

1 . A device comprising:
 a mask layer having a plurality of openings;   a III-nitride structure comprising:
 a plurality of posts of semiconductor material corresponding to the openings in the mask layer, each post comprising a light emitting layer, wherein the plurality of posts are separated by an insulating material; 
 wherein: 
 each light emitting layer is disposed between an n-type region and a p-type region; and 
 a first light emitting layer disposed in a first post is configured to emit light at a different wavelength than a second light emitting layer disposed in a second post. 
   
   
   
       2 . The device of  claim 1  wherein the III-nitride structure further comprises a planar layer of semiconductor material disposed over the plurality of posts. 
   
   
       3 . The device of  claim 1  wherein at least  90 % of a cross section of the plurality of posts in a plane parallel to a surface of the mask layer is occupied by posts. 
   
   
       4 . The device of  claim 1  wherein a portion of the posts are configured to emit blue light, a portion of the posts are configured to emit green light, and a portion of the posts are configured to emit red light. 
   
   
       5 . The device of  claim 1  wherein the first post has a different diameter than the second post. 
   
   
       6 . The device of  claim 1  wherein the first light emitting layer has a different InN composition than the second light emitting layer. 
   
   
       7 . The device of  claim 1  wherein the mask layer comprises silicon and nitrogen. 
   
   
       8 . The device of  claim 1  wherein each of the posts has a diameter less than 150 nm. 
   
   
       9 . The device of  claim 1  wherein the posts have a height between 50 nm and 3 μm. 
   
   
       10 . The device of  claim 1  wherein the insulating material is air. 
   
   
       11 . The device of  claim 1  wherein the light emitting layer has a thickness greater than 50 angstroms. 
   
   
       12 . The device of  claim 1  wherein the light emitting layer is doped with silicon to a dopant concentration between 1×10 18  cm −3  and 1×10 20  cm −3 . 
   
   
       13 . The device of  claim 1  further comprising:
 contacts electrically connected to the n-type region and the p-type region; and   a cover disposed over the III-nitride semiconductor structure.