Semiconductor light emitting element

• US 9,190,574 B2
• Filed: 08/21/2014
• Issued: 11/17/2015
• Est. Priority Date: 02/21/2012
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Hakuta, Shinya
• Primary Examiner(s): ENAD, CHRISTINE A
• Application Number:
  US14/465,354
• Publication Number:
  US 20140361330A1
• Time in Patent Office: 453 Days
• Field of Search: 257/98
• US Class Current: 1/1
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/30 containing only elements of Group III and Group V of the Periodic Table
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

A semiconductor light emitting element that outputs emitted light having a predetermined emitted light peak wavelength λ includes: at least a substrate; a lower distributed Bragg reflector layer provided on the substrate; and a light emitting layer provided on the lower distributed Bragg reflector layer. At least one phase changing layer having a thickness of mλ/2n (wherein n is the refractive index of the phase changing layer, and m is an integer 1 or greater) is provided within the lower distributed Bragg reflector layer.

Claims

1. A semiconductor light emitting element that outputs emitted light having a predetermined emitted light peak wavelength A, comprising at least:

a substrate;

a lower distributed Bragg reflector layer provided on the substrate; and

a light emitting layer provided on the lower distributed Bragg reflector layer;

at least one phase changing layer having a thickness of mλ

/2n (wherein n is the refractive index of the phase changing layer, and m is an integer 1 or greater) being provided within the lower distributed Bragg reflector layer;

a distributed Bragg reflector layer is not provided as a layer above the light emitting layer; and

an antireflection layer is provided as a layer above the light emitting layer;

the lower distributed Bragg reflector layer being equipped with a first distributed Bragg reflector layer and a second distributed Bragg reflector layer;

the at least one phase changing layer is provided between the first distributed Bragg reflector layer and the second distributed Bragg reflector layer; and

the antireflection layer being formed by a material having a refractive index lower than the refractive index of the light emitting layer.

2. A semiconductor light emitting element as defined in claim 1, wherein:

two phase changing layers are provided within the lower distributed Bragg reflector layer.

3. A semiconductor light emitting element as defined in claim 1, wherein:

the lower distributed Bragg reflector layer is basically constituted by two or more pairs of a low refractive index layer having a thickness a and a high refractive index layer having a thickness b which are alternately laminated; and

one of the low refractive index layers and the high refractive index layers constituting the phase changing layer having the thickness mλ

/2n, which is different from the thickness a and the thickness b.

4. A semiconductor light emitting element as defined in claim 1, wherein:

two of the phase changing layers are provided within the lower distributed Bragg reflector layer;

one of the two phase changing layers is one of the low refractive index layer and the high refractive index layer that constitutes the pair most toward the side of the light emitting layer; and

the other of the two phase changing layers the one phase changing layer provided between the first distributed Bragg reflector layer and the second distributed Bragg reflector, and is present within one of a range from 0.24 to 0.46 and a range from 0.66 to 0.82, when the lower distributed Bragg reflector layer is divided into percentages, with the side thereof toward the light emitting layer designated as 0, and the side thereof toward the substrate designated as 1.

5. A semiconductor light emitting element as defined in claim 4, wherein the other of the two phase changing layers is present within a range from 0.27 to 0.39 within the lower distributed Bragg reflector layer.

6. A semiconductor light emitting element as defined in claim 1, which is a light emitting diode of the surface emitting type.

7. A semiconductor light emitting element that outputs emitted light having a predetermined emitted light peak wavelength λ

, comprising at least;

a substrate;

a lower distributed Bragg reflector layer provided on the substrate; and

a light emitting layer provided on the lower distributed Bragg reflector layer;

an upper distributed Bragg reflector layer being provided as a layer above the light emitting layer;

two phase changing layers having a thickness of mλ

/2n (wherein n is the refractive index of the phase changing layer, and m is an integer 1 or greater) being provided within the lower distributed Bragg reflector layer;

one of the two phase changing layers is a low refractive index layer and a high refractive index layer that constitutes a pair most toward the side of the light emitting layer; and

the other of the two phase changing layers is present within one of a range from 0.22 to 0.33, when the lower distributed Bragg reflector layer is divided into percentages, with the side thereof toward the light emitting layer designated as 0, and the side thereof toward the substrate designated as 1.

8. A semiconductor light emitting element as defined in claim 7, wherein:

two phase changing layers are provided within the lower distributed Bragg reflector layer.

9. A semiconductor light emitting element as defined in claim 7, wherein:

the lower distributed Bragg reflector layer is basically constituted by two or more pairs of a low refractive index layer having a thickness a and a high refractive index layer having a thickness b which are alternately laminated; and

one of the low refractive index layers and the high refractive index layers constituting the phase changing layer having the thickness mλ

/2n, which is different from the thickness a and the thickness b.

10. A semiconductor light emitting element as defined in claim 7, which is a light emitting diode of the surface emitting type.