Electrode structure, and semiconductor light-emitting device having the same

Abstract

A semiconductor light emitting device including: a transparent substrate; an electron injection layer which is formed on the transparent substrate; an active layer which is formed on a first region of the electron injection layer; a hole injection layer which is formed on the active layer; a first electrode structure which is formed on the hole injection layer and concurrently provides a high reflectivity and a low contact resistance; a second electrode structure which is formed on a second region of the electron injection layer; and a circuit substrate which is electrically connected with the first and second electrode structures, the first electrode structure includes: a contact metal structure which has any one selected from the group consisting of nickel, palladium, platinum and ITO (Indium Tin Oxide) that have low contact resistance; and a reflective layer which has aluminum or silver.

1 . A semiconductor light emitting device comprising: 
 a transparent substrate;    an electron injection layer formed on the transparent substrate;    an active layer formed on a first region of the electron injection layer;    a hole injection layer formed on the active layer;    a first electrode structure which is formed on the hole injection layer and concurrently providing a high reflectivity and a low contact resistance;    a second electrode structure formed on a second region of the electron injection layer; and    a circuit substrate electrically connected with the first and second electrode structures.    
   
   
       2 . The light emitting device of  claim 1 , wherein the first electrode structure comprises: 
 a contact metal structure which has any one selected from the group consisting of nickel, palladium, platinum and ITO (Indium Tin Oxide) that have low contact resistance; and    a reflective layer formed on the contact metal structure.    
   
   
       3 . The light emitting device of  claim 2 , wherein the contact metal structure is island-shaped.  
   
   
       4 . The light emitting device of  claim 2 , wherein the contact metal structure is mesh-shaped.  
   
   
       5 . The light emitting device of  claim 3 , wherein an area ratio of the contact metal structure to the reflective layer is from 1% to 90%.  
   
   
       6 . The light emitting device of  claim 5 , wherein the thickness of the contact metal structure is less than 200 nm.  
   
   
       7 . The light emitting device of  claim 4 , wherein an area ratio of the contact metal structure to the reflective layer is from 1% to 90%.  
   
   
       8 . The light emitting device of  claim 7 , wherein the thickness of the contact metal structure is less than 200 nm.  
   
   
       9 . The light emitting device of  claim 2 , wherein the reflective layer is formed of aluminum (Al) or silver (Ag) that has a high reflectivity.  
   
   
       10 . The light emitting device of  claim 1 , wherein the transparent substrate is formed of sapphire.  
   
   
       11 . The light emitting device of  claim 1 , wherein the hole injection layer is formed of P-type GaN.  
   
   
       12 . An electrode structure used in a semiconductor light emitting device having an active layer and a hole injection layer formed on one surface of the active layer, the structure comprising: 
 a contact metal structure which is formed on one surface of the hole injection layer to face with the active layer, and has any one selected from the group consisting of nickel, palladium, platinum and ITO that have low contact resistance; and    a reflective layer formed on the contact metal structure.    
   
   
       13 . The electrode structure of  claim 12 , wherein the contact metal structure is island-shaped.  
   
   
       14 . The electrode structure of  claim 12 , wherein the contact metal structure is mesh-shaped.  
   
   
       15 . The electrode structure of  claim 13 , wherein an area ratio of the contact metal structure to the reflective layer is from 1% to 90%.  
   
   
       16 . The electrode structure of  claim 15 , wherein the thickness of the contact metal structure is less than 200 nm.  
   
   
       17 . The electrode structure of  claim 14 , wherein an area ratio of the contact metal structure to the reflective layer is from 1% to 90%.  
   
   
       18 . The electrode structure of  claim 17 , wherein the thickness of the contact metal structure is less than 200 nm.  
   
   
       19 . The electrode structure of  claim 12 , wherein the reflective layer is formed of aluminum (Al) or silver (Ag) that has a high reflectivity.  
   
   
       20 . The electrode structure of  claim 12 , wherein the hole injection layer is formed of P-type GaN