【特許請求の範囲】
【請求項１】
Ｉｎを含む窒化物半導体からなる少なくとも１つの第１の井戸層を有する第１の発光領域と、該第１の井戸層が発する光の主ピーク波長よりも長い主ピーク波長の光を発する、Ｉｎを含む窒化物半導体から成る少なくとも１つの第２の井戸層を有する第２の発光領域と、該第２の井戸層が発する光の主ピーク波長よりも長い主ピーク波長の光を発する、Ｉｎを含む窒化物半導体からなる少なくとも１つの第３の井戸層を有する第３の発光領域と、を備えた多重量子井戸構造から成る活性層を有する窒化物半導体発光素子において、
該活性層はｐ型窒化物半導体層側から見て、第１の発光領域、第３の発光領域、第２の発光領域の順で積層された構成を少なくとも１つ含んでなることを特徴とする窒化物半導体発光素子。
【請求項２】
Ｉｎを含む窒化物半導体からなる少なくとも１つの第１の井戸層を有する第１の発光領域と、該第１の井戸層が発する光の主ピーク波長よりも長い主ピーク波長の光を発する、Ｉｎを含む窒化物半導体から成る少なくとも１つの第２の井戸層を有する第２の発光領域と、該第２の井戸層が発する光の主ピーク波長よりも長い主ピーク波長の光を発する、Ｉｎを含む窒化物半導体からなる少なくとも１つの第３の井戸層を有する第３の発光領域と、を備えた多重量子井戸構造から成る活性層を有する窒化物半導体発光素子において、
該活性層はｐ型窒化物半導体層側から見て、第１の発光領域、第３の発光領域、第２の発光領域の順で積層された構成のみから成ることを特徴とする窒化物半導体発光素子。
【請求項３】
Ｉｎを含む窒化物半導体からなる少なくとも１つの第１の井戸層と、該第１の井戸層が発する光の主ピーク波長よりも長い主ピーク波長の光を発する、Ｉｎを含む窒化物半導体から成る少なくとも１つの第２の井戸層と、該第２の井戸層が発する光の主ピーク波長よりも長い主ピーク波長の光を発する、Ｉｎを含む窒化物半導体からなる少なくとも１つの第３の井戸層と、を備えた多重量子井戸構造から成る活性層を有する窒化物半導体発光素子において、
活性層はｐ型窒化物半導体層側から見て、障壁層、第１の井戸層、障壁層、第３の井戸層、障壁層、第２の井戸層、障壁層の順で積層された構成を少なくとも１つ含むことを特徴とする窒化物半導体発光素子。
【請求項４】
Ｉｎを含む窒化物半導体からなる少なくとも１つの第１の井戸層と、該第１の井戸層が発する光の主ピーク波長よりも長い主ピーク波長の光を発する、Ｉｎを含む窒化物半導体から成る少なくとも１つの第２の井戸層と、該第２の井戸層が発する光の主ピーク波長よりも長い主ピーク波長の光を発する、Ｉｎを含む窒化物半導体からなる少なくとも１つの第３の井戸層と、を備えた多重量子井戸構造から成る活性層を有する窒化物半導体発光素子において、
活性層はｐ型窒化物半導体層側から見て、障壁層、第１の井戸層、障壁層、第３の井戸層、障壁層、第２の井戸層、障壁層の順で積層された構成のみからなることを特徴とする窒化物半導体発光素子。
【請求項５】
上記第１の井戸層が発する光の主ピーク波長が４００乃至４８０ｎｍで、上記第２の井戸層が発する光の主ピーク波長が４８０乃至５７０ｎｍで、上記第３の井戸層が発する光の主ピーク波長が５７０乃至８００ｎｍであることを特徴とする請求項１乃至請求項４のいずれかに記載の窒化物半導体発光素子。
【請求項６】
上記第１の井戸層が発する光の主ピーク波長が４２０乃至４６０ｎｍ、上記第２の井戸層が発する光の主ピーク波長が４８０乃至５２０ｎｍ、上記第３の主ピーク波長が５７０乃至６００ｎｍであることを特徴とする請求項１乃至請求項５のいずれか１項に記載の窒化物半導体発光素子。
【請求項７】
基板上に、ｎ型窒化物半導体層、活性層、ｐ型窒化物半導体層を順に有し、
前記活性層は、Ｉｎを含む窒化物半導体からなるｎ個（ｎ≧４）の井戸層を備えた多重量子井戸構造からなり、第１の井戸層、第２の井戸層、・・・、第ｎの井戸層の順に主ピーク波長が短い窒化物半導体発光素子において、
主ピーク波長が最も短い第１の井戸層をｐ型窒化物半導体層の最も近くに有し、その次にｐ型窒化物半導体層に近い位置に、主ピーク波長が最も長い第ｎの井戸層を有することを特徴とする窒化物半導体発光素子。
【請求項８】
前記ｎ型半導体層は超格子層を有することを特徴とする請求項１乃至７のいずれか１項に記載の窒化物半導体発光素子。
【請求項９】
前記超格子層は、アンドープＧａＮとＳｉドープＧａＮからなることを特徴とする請求項８に記載の窒化物半導体発光素子。
[Claims]
[Claim 1]
In, which emits light having a first light emitting region having at least one first well layer made of a nitride semiconductor containing In, and a main peak wavelength longer than the main peak wavelength of the light emitted by the first well layer. A second light emitting region having at least one second well layer made of a nitride semiconductor including, and In, which emits light having a main peak wavelength longer than the main peak wavelength of the light emitted by the second well layer. In a nitride semiconductor light emitting element having an active layer having a multiple quantum well structure including a third light emitting region having at least one third well layer made of a nitride semiconductor containing the light emitting region.
The active layer is characterized by including at least one structure in which a first light emitting region, a third light emitting region, and a second light emitting region are laminated in this order when viewed from the p-type nitride semiconductor layer side. Nitride semiconductor light emitting device.
2.
In, which emits light having a first light emitting region having at least one first well layer made of a nitride semiconductor containing In, and a main peak wavelength longer than the main peak wavelength of the light emitted by the first well layer. A second light emitting region having at least one second well layer made of a nitride semiconductor including, and In, which emits light having a main peak wavelength longer than the main peak wavelength of the light emitted by the second well layer. In a nitride semiconductor light emitting element having an active layer having a multiple quantum well structure including a third light emitting region having at least one third well layer made of a nitride semiconductor containing the light emitting region.
The nitride semiconductor is characterized in that the active layer is composed only of a structure in which a first light emitting region, a third light emitting region, and a second light emitting region are laminated in this order when viewed from the p-type nitride semiconductor layer side. Light emitting element.
3.
It is composed of at least one first well layer made of a nitride semiconductor containing In, and a nitride semiconductor containing In that emits light having a main peak wavelength longer than the main peak wavelength of the light emitted by the first well layer. At least one second well layer and at least one third well layer composed of an In-containing nitride semiconductor that emits light having a main peak wavelength longer than the main peak wavelength of the light emitted by the second well layer. In a nitride semiconductor light emitting element having an active layer having a multiple quantum well structure including
The active layer has a structure in which the barrier layer, the first well layer, the barrier layer, the third well layer, the barrier layer, the second well layer, and the barrier layer are laminated in this order when viewed from the p-type nitride semiconductor layer side. A nitride semiconductor light emitting device, characterized in that it contains at least one of.
4.
It is composed of at least one first well layer made of a nitride semiconductor containing In, and a nitride semiconductor containing In that emits light having a main peak wavelength longer than the main peak wavelength of the light emitted by the first well layer. At least one second well layer and at least one third well layer composed of an In-containing nitride semiconductor that emits light having a main peak wavelength longer than the main peak wavelength of the light emitted by the second well layer. In a nitride semiconductor light emitting element having an active layer having a multiple quantum well structure including
The active layer has a structure in which the barrier layer, the first well layer, the barrier layer, the third well layer, the barrier layer, the second well layer, and the barrier layer are laminated in this order when viewed from the p-type nitride semiconductor layer side. A nitride semiconductor light emitting device characterized by consisting of only a well.
5.
The main peak wavelength of the light emitted by the first well layer is 400 to 480 nm, the main peak wavelength of the light emitted by the second well layer is 480 to 570 nm, and the main peak of the light emitted by the third well layer is 480 to 570 nm. The nitride semiconductor light emitting device according to any one of claims 1 to 4, wherein the wavelength is 570 to 800 nm.
6.
The main peak wavelength of the light emitted by the first well layer is 420 to 460 nm, the main peak wavelength of the light emitted by the second well layer is 480 to 520 nm, and the third main peak wavelength is 570 to 600 nm. The nitride semiconductor light emitting device according to any one of claims 1 to 5.
7.
The n-type nitride semiconductor layer, the active layer, and the p-type nitride semiconductor layer are sequentially provided on the substrate.
The active layer has a multiple quantum well structure including n (n ≧ 4) well layers made of nitride semiconductors containing In, and has a first well layer, a second well layer, ..., First. In the nitride semiconductor light emitting device in which the main peak wavelength is shorter in the order of n well layers,
The first well layer having the shortest main peak wavelength is located closest to the p-type nitride semiconductor layer, and the nth well layer having the longest main peak wavelength is located next to the p-type nitride semiconductor layer. Nitride semiconductor light emitting device.
8.
The nitride semiconductor light emitting device according to any one of claims 1 to 7, wherein the n-type semiconductor layer has a superlattice layer.
9.
The nitride semiconductor light emitting device according to claim 8, wherein the superlattice layer is composed of undoped GaN and Si-doped GaN.
また、本発明は第１の井戸層が発する光の主ピーク波長が４２０乃至４６０ｎｍ、上記第２の井戸層が発する光の主ピーク波長が４８０乃至５２０ｎｍ、上記第３の主ピーク波長が５７０乃至６００ｎｍであることを特徴とする。この構成により赤色領域程度の長波長で発光する井戸層を設けることなく所望の演色性を有する白色光の発光効率の高い窒化物半導体発光素子を得ることができる。
また、本発明の窒化物半導体発光素子は、基板上に、ｎ型窒化物半導体層、活性層、ｐ型窒化物半導体層を順に有し、前記活性層は、Ｉｎを含む窒化物半導体からなるｎ個（ｎ≧４）の井戸層を備えた多重量子井戸構造からなり、第１の井戸層、第２の井戸層、・・・、第ｎの井戸層の順に主ピーク波長が短い窒化物半導体発光素子において、主ピーク波長が最も短い第１の井戸層をｐ型窒化物半導体層の最も近くに有し、その次にｐ型窒化物半導体層に近い位置に、主ピーク波長が最も長い第ｎの井戸層を有することを特徴とする。
また、本発明の窒化物半導体発光素子は、ｎ型半導体層に超格子層を有することを特徴とする。また、超格子層は、アンドープＧａＮとＳｉドープＧａＮからなることを特徴とする。
Further, in the present invention, the main peak wavelength of the light emitted by the first well layer is 420 to 460 nm, the main peak wavelength of the light emitted by the second well layer is 480 to 520 nm, and the third main peak wavelength is 570 or more. It is characterized by having a wavelength of 600 nm. With this configuration, it is possible to obtain a nitride semiconductor light emitting device having a desired color rendering property and having high luminous efficiency of white light without providing a well layer that emits light at a long wavelength of about the red region.
Further, the nitride semiconductor light emitting device of the present invention has an n-type nitride semiconductor layer, an active layer, and a p-type nitride semiconductor layer in this order on a substrate, and the active layer is made of a nitride semiconductor containing In. A nitride structure consisting of multiple quantum well structures with n (n ≧ 4) well layers, with shorter main peak wavelengths in the order of the first well layer, the second well layer, ..., The nth well layer. In a semiconductor light emitting element, the first well layer having the shortest main peak wavelength is located closest to the p-type nitride semiconductor layer, and then the first well layer having the shortest main peak wavelength is located closest to the p-type nitride semiconductor layer, and the main peak wavelength is the longest. It is characterized by having an nth well layer.
Further, the nitride semiconductor light emitting device of the present invention is characterized by having a superlattice layer in the n-type semiconductor layer. Further, the superlattice layer is characterized in that it is composed of undoped GaN and Si-doped GaN.