Semiconductor light emitting device

Abstract

A semiconductor light emitting device includes a first semiconductor layer, an active layer disposed on the first semiconductor layer to emit ultraviolet light, a second semiconductor layer disposed on the active layer, and a first electrode disposed on the first semiconductor layer and being in Ohmic contact with a portion of the first semiconductor layer, the first electrode including a contact electrode including aluminum (Al) and at least one other material and having a first region adjacent to the first semiconductor layer and a second region, with each region having an Al composition ratio defined by the amount of Al relative to the amount of the at least one other material, wherein the Al composition ratio of the first region is greater than the Al composition ratio of the second region, and a metal layer disposed on the contact electrode.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]This application claims priority from and the benefit of Korean Patent Application No. 10-2016-0178046 filed on Dec. 23, 2016, which is hereby incorporated by reference for all purposes as if fully set forth herein.BACKGROUNDField[0002]Exemplary implementations of the invention relate generally to an electronic device and, more particularly, to a semiconductor light emitting device including a light emitting structure, such as a light emitting diode, capable of emitting deep ultraviolet light.Discussion of the Background[0003]Semiconductor light emitting diodes (LEDs) are devices in which light is emitted by a material contained in a device using electric energy, and have inorganic semiconductors emitting light generated by recombination of electrons and holes. Semiconductor light emitting diodes (LEDs) have a number of advantages over filament-based light sources, such as long lifetime, low power, and good initial drive characteristics, a...

AI Technical Summary

Benefits of technology

This patent describes a way to make semiconductor light emitting devices that can produce DUV light and have better voltage characteristics and efficiency. One way to improve this is by partially alloying the internal layers, such as the contact electrode, so that the amount of aluminum in the layer changes as it goes deeper. Another way is to add a reflective layer to the metal layer to reflect light, and a barrier layer to prevent metal atoms or ions from diffusing into the reflective layer. These improvements can lead to better performance of the light emitting devices.

Problems solved by technology

However, since a significant amount of light emitted from the multiple quantum well structure is absorbed in the p-type contact layer, light efficiency of conventional UV semiconductor light emitting devices has been very low.

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