High brightness light emitting diode covered by zinc oxide layers on multiple surfaces grown in low temperature aqueous solution

Abstract

A high brightness III-Nitride based Light Emitting Diode (LED), comprising multiple surfaces covered by Zinc Oxide (ZnO) layers, wherein the ZnO layers are grown in a low temperature aqueous solution and each have a (0001) c-orientation and a top surface that is a (0001) plane.

What is claimed is: 
     
         1 . An optoelectronic device, comprising:
 a III-Nitride Light Emitting Diode (LED) wherein one or more non-polar or semi-polar III-nitride light transmitting surfaces of the LED are covered by one or more Zinc Oxide (ZnO) layers.   
     
     
         2 . The device of  claim 1 , wherein the ZnO layers are non-epitaxial with respect to the underlying non-polar or semi-polar III-nitride light transmitting surface. 
     
     
         3 . The device of  claim 1 , wherein the LED is a non-polar LED. 
     
     
         4 . The device of  claim 1 , wherein the LED is a semi-polar LED. 
     
     
         5 . The device of  claim 1 , wherein one or more of the ZnO layers include at least one epitaxial ZnO layer. 
     
     
         6 . The device of  claim 1 , wherein one or more of the ZnO layers include one or more polycrystalline ZnO layers with a preferential crystalline grain texture such that, on average, ZnO crystals in the polycrystalline ZnO layers are oriented with their [0001] c-direction perpendicular to the covered light transmitting surfaces. 
     
     
         7 . The device of  claim 1 , wherein:
 one or more of the ZnO layers include one or more epitaxial ZnO layers, and   one or more of the ZnO layers include one or more polycrystalline ZnO layers with a preferential crystalline grain texture such that, on average, ZnO crystals in the polycrystalline ZnO layers are oriented with their [0001] c-direction perpendicular to the covered light transmitting surfaces.   
     
     
         8 . The device of  claim 1 , wherein the III-Nitride LED is a conventional LED grown on a heteroepitaxial substrate. 
     
     
         9 . The device of  claim 1 , wherein the III-Nitride LED is a homoepitaxial LED grown on a bulk GaN substrate. 
     
     
         10 . The device of  claim 1 , wherein the III-Nitride LED is a lateral (mesa) architecture type device. 
     
     
         11 . The device of  claim 1 , wherein the III-Nitride LED is a vertical architecture type device. 
     
     
         12 . The device of  claim 1 , wherein a p-type III-Nitride surface of the device is a light transmitting surface and is covered by at least one of the ZnO layers. 
     
     
         13 . The device of  claim 1 , wherein a p-type III-Nitride surface of the device is not a light transmitting surface and is covered by a reflective p-contact layer. 
     
     
         14 . The device of  claim 1 , wherein one or more of the ZnO layers are roughened in a way that increases light extraction from the LED. 
     
     
         15 . The device of  claim 1 , further comprising:
 a III-nitride n-type layer;   a III-nitride p-type layer;   a III-nitride active layer, for emitting light, between the n-type layer and the p-type layer, wherein:   (1) a plurality of light transmitting surfaces, wherein the light transmitting surfaces include a bottom surface of the LED, sidewalls of the LED, and a top surface of the LED, and   (2) at least one of the ZnO layers is on each of the light transmitting surfaces and the ZnO layers increase light extraction from the LED.