Light emitting diode and manufacturing method thereof

Abstract

A light emitting diode includes: a substrate; an n-type semiconductor layer disposed on the substrate; an active layer disposed on the n-type semiconductor layer; a p-type semiconductor layer disposed on the active layer; a first electrode disposed on the p-type semiconductor layer and made of a metal oxide; a second electrode disposed on the first electrode and made of graphene; a p-type electrode disposed on the second electrode; and an n-type electrode disposed on the n-type semiconductor layer, wherein a work function of the first electrode is less than a work function of the p-type semiconductor layer, but is greater than a to work function of the second electrode.

What is claimed is: 
     
         1 . A light emitting diode comprising:
 a substrate;   an n-type semiconductor layer disposed on the substrate;   an active layer disposed on the n-type semiconductor layer;   a p-type semiconductor layer disposed on the active layer;   a first electrode disposed on the p-type semiconductor layer and made of a metal oxide;   a second electrode disposed on the first electrode and made of graphene;   a p-type electrode disposed on the second electrode; and   an n-type electrode disposed on the n-type semiconductor layer,   wherein a work function of the first electrode is less than a work function of the p-type semiconductor layer, but is greater than a work function of the second electrode.   
     
     
         2 . The light emitting diode of  claim 1 , wherein the first electrode has a net structure. 
     
     
         3 . The light emitting diode of  claim 2 , wherein the first electrode comprises:
 a plurality of first conductive patterns having a circle shape or a polygon shape and arranged in a matrix;   a plurality of second conductive patterns protruding from the first conductive patterns to connect adjacent first conductive patterns to each other; and   a plurality of third conductive patterns protruding in a direction perpendicular to the second conductive patterns from the first conductive patterns to connect adjacent first conductive patterns to each other,   wherein the second conductive patterns and the third conductive patterns are linear.   
     
     
         4 . The light emitting diode of  claim 2 , wherein the first electrode has a line width in a range of 10 nm to 100 nm. 
     
     
         5 . The light emitting diode of  claim 1 , wherein the first electrode comprises at least one of ITO, ZnO, SnO 2 , TiO 2 , SbO 2 , NiO, CrO, and CuO.