NITRIDE SEMICONDUCTOR LIGHT-EMITTING DIODE
First Claim
1. A nitride semiconductor light-emitting diode comprising:
- an n-side electrode;
a p-side electrode;
a first n-type nitride semiconductor layer;
a p-type nitride semiconductor layer;
a second n-type nitride semiconductor layer; and
an active layer interposed between the first n-type nitride semiconductor layer and the p-type nitride semiconductor layer, whereinthe n-side electrode is electrically connected to the first n-type nitride semiconductor layer;
the p-side electrode is electrically connected to the p-type nitride semiconductor layer;
the active layer is composed of a single quantum well layer;
the single quantum well layer is formed of n-type InGaN;
the active layer has a principal surface of an m-plane having an off angle of not less than 0 degrees and not more than 15 degrees;
the active layer has a thickness of not less than 6 nanometers;
the second n-type nitride semiconductor layer is interposed between the active layer and the p-type nitride semiconductor layer;
either of the following requirement (A) and (B) is satisfied;
(A) the second n-type nitride semiconductor layer has a donor impurity concentration of not less than 3.0×
1017 cm−
3 and less than 1.5×
1018 cm−
3, and the p-type nitride semiconductor layer has an acceptor impurity concentration of not less than 5.0×
1017 cm−
3 and less than 1.0×
1018 cm−
3, or(B) the second n-type nitride semiconductor layer has a donor impurity concentration of not less than 3.0×
1017 cm−
3 and not more than 2.5×
1018 cm−
3, and the p-type nitride semiconductor layer has an acceptor impurity concentration of not less than 1.0×
1018 cm−
3;
the second n-type nitride semiconductor layer has a thickness of not less than 25 nanometers; and
the following mathematical formula (I) is satisfied;
(Efficiency Decrease Degree at low current density Δ
EQE@0.3 A/cm2)≦
0.6
(I),where
(Efficiency Decrease Degree at low current density Δ
EQE@0.3 A/cm2)=(EQEmax−
EQE@0.3 A/cm2)/EQEmax;
EQEmax represents the maximum of an external quantum efficiency of the nitride semiconductor light-emitting diode; and
EQE@0.3 A/cm2 represents an external quantum efficiency of the nitride semiconductor light-emitting diode when a current of 0.3 A/cm2 flows through the nitride semiconductor light-emitting diode.
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0 Petitions
Accused Products
Abstract
Provided is a nitride semiconductor light-emitting diode in which efficiency in a low current density is prevented from being decreased. The nitride semiconductor light-emitting diode comprises a second n-type nitride semiconductor layer. An active layer has a principal surface of an m-plane having an off angle of not less than 0 degrees and not more than 15 degrees. Either of the following requirement (A) and (B) is satisfied; (A) the second n-type nitride semiconductor layer has a donor impurity concentration of not less than 3.0×1017 cm−3 and less than 1.5×1018 cm−3, and the p-type nitride semiconductor has an acceptor impurity concentration of not less than 5.0×1017 cm−3 and less than 1.0×1018 cm−3, or (B) the second n-type nitride semiconductor layer has a donor impurity concentration of not less than 3.0×1017 cm−3 and not more than 2.5×1018 cm−3, and the p-type nitride semiconductor has an acceptor impurity concentration of not less than 1.0×1018 cm−3.
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Citations
8 Claims
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1. A nitride semiconductor light-emitting diode comprising:
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an n-side electrode; a p-side electrode; a first n-type nitride semiconductor layer; a p-type nitride semiconductor layer; a second n-type nitride semiconductor layer; and an active layer interposed between the first n-type nitride semiconductor layer and the p-type nitride semiconductor layer, wherein the n-side electrode is electrically connected to the first n-type nitride semiconductor layer; the p-side electrode is electrically connected to the p-type nitride semiconductor layer; the active layer is composed of a single quantum well layer; the single quantum well layer is formed of n-type InGaN; the active layer has a principal surface of an m-plane having an off angle of not less than 0 degrees and not more than 15 degrees; the active layer has a thickness of not less than 6 nanometers; the second n-type nitride semiconductor layer is interposed between the active layer and the p-type nitride semiconductor layer; either of the following requirement (A) and (B) is satisfied; (A) the second n-type nitride semiconductor layer has a donor impurity concentration of not less than 3.0×
1017 cm−
3 and less than 1.5×
1018 cm−
3, and the p-type nitride semiconductor layer has an acceptor impurity concentration of not less than 5.0×
1017 cm−
3 and less than 1.0×
1018 cm−
3, or(B) the second n-type nitride semiconductor layer has a donor impurity concentration of not less than 3.0×
1017 cm−
3 and not more than 2.5×
1018 cm−
3, and the p-type nitride semiconductor layer has an acceptor impurity concentration of not less than 1.0×
1018 cm−
3;the second n-type nitride semiconductor layer has a thickness of not less than 25 nanometers; and the following mathematical formula (I) is satisfied;
(Efficiency Decrease Degree at low current density Δ
EQE@0.3 A/cm2)≦
0.6
(I),where
(Efficiency Decrease Degree at low current density Δ
EQE@0.3 A/cm2)=(EQEmax−
EQE@0.3 A/cm2)/EQEmax;EQEmax represents the maximum of an external quantum efficiency of the nitride semiconductor light-emitting diode; and EQE@0.3 A/cm2 represents an external quantum efficiency of the nitride semiconductor light-emitting diode when a current of 0.3 A/cm2 flows through the nitride semiconductor light-emitting diode. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A nitride semiconductor light-emitting diode comprising:
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an n-side electrode; a p-side electrode; a first n-type nitride semiconductor layer; a p-type nitride semiconductor layer; a second n-type nitride semiconductor layer; and an active layer interposed between the first n-type nitride semiconductor layer and the p-type nitride semiconductor layer, wherein the n-side electrode is electrically connected to the first n-type nitride semiconductor layer; the p-side electrode is electrically connected to the p-type nitride semiconductor layer; the active layer is composed of a single quantum well layer; the single quantum well layer is formed of n-type InGaN; the active layer has a principal surface of an m-plane having an off angle of not less than 0 degrees and not more than 15 degrees; the active layer has a thickness of not less than 6 nanometers; the second n-type nitride semiconductor layer is interposed between the active layer and the p-type nitride semiconductor layer; either of the following requirement (A) and (B) is satisfied; (A) the second n-type nitride semiconductor layer has a donor impurity concentration of not less than 3.0×
1017 cm−
3 and less than 1.5×
1018 cm−
3, and the p-type nitride semiconductor layer has an acceptor impurity concentration of not less than 5.0×
1017 cm−
3 and less than 1.0×
1018 cm−
3, or(B) the second n-type nitride semiconductor layer has a donor impurity concentration of not less than 3.0×
1017 cm−
3 and not more than 2.5×
1018 cm−
3, and the p-type nitride semiconductor layer has an acceptor impurity concentration of not less than 1.0×
1018 cm−
3;the second n-type nitride semiconductor layer has a thickness of not less than 25 nanometers.
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8. A nitride semiconductor light-emitting diode comprising:
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an n-side electrode; a p-side electrode; a first n-type nitride semiconductor layer; a p-type nitride semiconductor layer; a second n-type nitride semiconductor layer; and an active layer interposed between the first n-type nitride semiconductor layer and the p-type nitride semiconductor layer, wherein the n-side electrode is electrically connected to the first n-type nitride semiconductor layer; the p-side electrode is electrically connected to the p-type nitride semiconductor layer; the active layer is composed of a single quantum well layer; the single quantum well layer is formed of n-type InGaN; the following mathematical formula (I) is satisfied;
(Efficiency Decrease Degree at low current density Δ
EQE@0.3 A/cm2)≦
0.6
(I),where
(Efficiency Decrease Degree at low current density Δ
EQE@0.3 A/cm2)=(EQEmax−
EQE@0.3 A/cm2)/EQEmax;EQEmax represents the maximum of an external quantum efficiency of the nitride semiconductor light-emitting diode; and EQE@0.3 A/cm2 represents an external quantum efficiency of the nitride semiconductor light-emitting diode when a current of 0.3 A/cm2 flows through the nitride semiconductor light-emitting diode.
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Specification