Method for manufacturing super bright light emitting diode of nanorod array having InGaN quantum well
View Patent ↗An GaN light emitting diode (LED) having a nanorod (or, nanowire) structure is disclosed. The GaN LED employs GaN nanorods in which a n-type GaN nanorod, an InGaN quantum well and a p-type GaN nanorod are subsequently formed in a longitudinal direction by inserting the InGaN quantum well into a p-n junction interface of the p-n junction GaN nanorod. In addition, a plurality of such GaN nanorods are arranged in an array so as to provide an LED having much greater brightness and higher light emission efficiency than a conventional laminated-film GaN LED.
1. A method for manufacturing a light emitting diode (LED), comprising:
forming a plurality of first-conductive type GaN nanorods in an array perpendicular to a substrate;
forming an InGaN quantum well on each first-conductive type GaN nanorod;
forming a second-conductive type GaN nanorod on each InGaN quantum well;
forming an electrode pad for applying voltage to the first-conductive type GaN nanorods; and
forming a transparent electrode to be commonly connected to the second-conductive type GaN nanorods for supplying voltage thereto.
2. A method for manufacturing an LED according to claim 1 , further comprising, after the step of forming the second-conductive type GaN nanorods:
filling a transparent insulating material among the nanorods including the first-conductive type GaN nanorods, the InGaN quantum wells and the second-conductive type GaN nanorods.
3. A method for manufacturing an LED according to claim 2 , wherein the transparent insulating material is SOG (Spin-On-Glass), SiO2 or an epoxy resin.
4. A method for manufacturing an LED according to claim 2 , wherein a fluorescent material is added to the transparent insulating material so that a light emitted from the LED becomes a white light as a whole.
5. A method for manufacturing an LED according to claim 1 ,
wherein the quantum well forming step repeatedly forms InGaN layers and GaN barrier layers in turns so as to form a multi quantum well.
6. A method for manufacturing an LED according to claim 1 ,
wherein the first-conductive type GaN nanorods, the InGaN quantum wells and the second-conductive type GaN nanorods are formed in-situ using MO-HVPE (metalorganic-hydride vapor phase epitaxy).
7. A method for manufacturing an LED according to claim 1 ,
wherein the substrate is a sapphire substrate,
wherein the method further comprises a step of forming a first-conductive type GaN buffer layer on the sapphire substrate before the first-conductive type GaN nanorod forming step, and
wherein the electrode pad is formed on a part of the GaN buffer layer.
8. A method for manufacturing an LED according to claim 1 ,
wherein the substrate is a silicon substrate,
wherein the electrode pad is formed on a surface of the silicon opposed to a surface formed by the nanorods.