Low optical loss electrode structures for LEDs
First Claim
1. An electrode structure for interfacing with a semiconductor material in which is formed a PN junction capable of generating light responsive to application of a potential across the PN junction, the electrode structure comprising:
- a metal electrode;
a non-perforated region of dielectric material disposed between the metal electrode and a surface of the semiconductor material, the non-perforated region of dielectric material having an index of refraction greater than or equal to one and less than that of a semiconductor upon which the non-perforated region of dielectric material is formed; and
an optically transmissive ohmic contact layer establishing ohmic contact between the metal electrode and the semiconductor material, wherein the metal electrode is physically separated from the surface of the semiconductor material by one or more of the optically transmissive ohmic contact layer and the non-perforated region of dielectric material, whereinthe electrode structure and the non-perforated region of dielectric material are relatively disposed for conduction of electric current through the electrode structure to the semiconductor material only at a periphery of the non-perforated layer of dielectric material, and light generated by the PN junction is emitted through the optically transmissive ohmic contact layer.
3 Assignments
0 Petitions
Accused Products
Abstract
An electrode structure is disclosed for enhancing the brightness and/or efficiency of an LED. The electrode structure can have a metal electrode and an dielectric material formed intermediate the electrode and a light emitting semiconductor material. Electrical continuity between the semiconductor material and the metal electrode is provided by an optically transmissive ohmic contact layer, such as a layer of Indium Tin Oxide. The metal electrode thus can be physically separated from the semiconductor material by one or more of the dielectric material and the ohmic contact layer. The dielectric layer can increase total internal reflection of light at the interface between the semiconductor and the dielectric layer, which can reduce absorption of light by the electrode. Such LED can have enhanced utility and can be suitable for uses such as general illumination.
50 Citations
15 Claims
-
1. An electrode structure for interfacing with a semiconductor material in which is formed a PN junction capable of generating light responsive to application of a potential across the PN junction, the electrode structure comprising:
-
a metal electrode; a non-perforated region of dielectric material disposed between the metal electrode and a surface of the semiconductor material, the non-perforated region of dielectric material having an index of refraction greater than or equal to one and less than that of a semiconductor upon which the non-perforated region of dielectric material is formed; and an optically transmissive ohmic contact layer establishing ohmic contact between the metal electrode and the semiconductor material, wherein the metal electrode is physically separated from the surface of the semiconductor material by one or more of the optically transmissive ohmic contact layer and the non-perforated region of dielectric material, wherein the electrode structure and the non-perforated region of dielectric material are relatively disposed for conduction of electric current through the electrode structure to the semiconductor material only at a periphery of the non-perforated layer of dielectric material, and light generated by the PN junction is emitted through the optically transmissive ohmic contact layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. An electrode structure for interfacing with a semiconductor material in which is formed a Light Emitting Diode (LED) device, the electrode structure comprising:
-
a metal electrode supported from a planar surface of the semiconductor material; a non-perforated layer of dielectric material disposed between the metal electrode and the surface of the semiconductor material, the non-perforated layer of dielectric material having an index of refraction greater than or equal to one and less than that of the semiconductor material, the non-perforated layer of dielectric material covering only a portion of the planar surface of the semiconductor material; and an optically transmissive ohmic contact layer contacting the electrode and the surface of the semiconductor in an area of the surface of the semiconductor material not covered by the non-perforated layer of dielectric material or the metal electrode, wherein current flow occurs at a periphery of the non-perforated layer of dielectric material responsive to a potential applied to the metal electrode, and a metal electrode in ohmic contact with an opposite polarity surface. - View Dependent Claims (13, 14, 15)
-
Specification