Light emitting diode and method for improving luminescence efficiency of light emitting diode

Abstract

A light emitting diode comprising a semiconductor layer, a first electrode, a second electrode and a diamond-like carbon layer is provided. The semiconductor layer includes a first type doped semiconductor layer, a light emitting layer and a second type doped semiconductor layer. Wherein, the light emitting layer locates between the first type doped semiconductor layer and the second type doped semiconductor layer. The first electrode is electrically connected to the first type doped semiconductor layer. The second electrode is electrically connected to the second type doped semiconductor layer. The diamond-like carbon layer covers on the semiconductor layer and exposes at least a portion of the first electrode. Moreover, the exposed outer surface of the diamond-like carbon layer is a rough surface. Alternatively, other passivation layer with rough surface can be substituted for the diamond-like carbon layer.

1 . A method for improving luminescence efficiency of a light emitting device, comprising the steps of: 
 providing a light emitting diode, the light emitting diode at least includes a semiconductor layer, a first electrode and a second electrode; and    forming a diamond-like carbon layer on the light emitting diode, the diamond-like carbon layer covers on the semiconductor layer and exposes at least a portion of the first electrode.    
   
   
       2 . The method for improving luminescence efficiency of a light emitting device according to  claim 1 , wherein after the diamond-like carbon layer is formed, further comprising proceeding a surface roughening step on the diamond-like carbon layer.  
   
   
       3 . The method for improving luminescence efficiency of a light emitting device according to  claim 2 , wherein the surface roughening step includes a reactive ion etching.  
   
   
       4 . A method for improving luminescence efficiency of a light emitting device, comprising the steps of: 
 providing a light emitting diode, the light emitting diode at least includes a semiconductor layer, a first electrode, a second electrode and a passivation layer, wherein the passivation layer covers on the semiconductor layer and exposes at least a portion of the first electrode; and    proceeding a surface roughening step on the passivation layer.    
   
   
       5 . The method for improving luminescence efficiency of a light emitting device according to  claim 4 , wherein the surface roughening step includes a reactive ion etching.