Abstract: According to one embodiment, a semiconductor light emitting device includes an n-type semiconductor layer, a p-type semiconductor layer, and a light emitting portion. The light emitting portion is provided between the semiconductor layers and includes barrier layers and well layers alternately stacked. An n-side end well layer which is closest to the n-type semiconductor layer contains InwnGa1-wnN and has a layer thickness twn. An n-side end barrier layer which is closest to the n-type semiconductor layer contains InbnGa1-bnN and has a layer thickness tbn. A p-side end well layer which is closest to the p-type semiconductor layer contains InwpGa1-wpN and has a layer thickness twp. A p-side end barrier layer which is closest to the p-type semiconductor contains InbpGa1-bpN and has a layer thickness tbp. A value of (wp×twp+bp×tbp)/(twp+tbp) is higher than (wn×twn+bn×tbn)/(twn+tbn) and is not higher than 5 times (wn×twn+bn×tbn)/(twn+tbn).

Abstract: According to one embodiment, a semiconductor light-emitting device includes an n-type semiconductor layer including a nitride semiconductor, a p-type semiconductor layer including a nitride semiconductor, a light-emitting portion and a stacked body. The light-emitting portion is provided between the n-type and p-type semiconductor layers and includes a barrier layer and a well layer. The well layer is stacked with the barrier layer. The stacked body is provided between the light-emitting portion and the n-type semiconductor layer and includes a first layer and a second layer. The second layer is stacked with the first layer. Average In composition ratio of the stacked body is higher than 0.4 times average In composition ratio of the light-emitting portion. The layer thickness tb of the barrier layer is 10 nanometers or less.

Abstract: According to one embodiment, a semiconductor light emitting device includes a first semiconductor layer, a second semiconductor layer, a light emitting part, and a multilayered structural body. The light emitting part is provided between the first and second semiconductor layers and includes barrier layers and well layers alternately stacked. The multilayered structural body is provided between the first semiconductor layer and the light emitting part and includes high energy layers and low energy layers alternately stacked. An average In composition ratio on a side of the second semiconductor is higher than that on a side of the first semiconductor in the multilayered structural body. An average In composition ratio on a side of the second semiconductor is higher than that on a side of the first semiconductor in the light emitting part.

Abstract: In general, according to one embodiment, a semiconductor light emitting element includes: a first semiconductor layer; a second semiconductor layer; a light emitting layer. The light emitting layer includes a well layer with a thickness of t1 (nanometers). The well layer includes InxGa1-xN having an In composition ratio x higher than 0 and lower than 1. The first semiconductor layer has a tensile strain of not less than 0.02 percent and not more than 0.25 percent in a plane perpendicular to a stacking direction. A peak wavelength ?p (nanometers) of light satisfies a relationship of ?p=a1+a2×(x+(t1?3.0)×a3). The a1 is not less than 359 and not more than 363. The a2 is not less than 534 and not more than 550. The a3 is not less than 0.0205 and not more than 0.0235.

Abstract: According to one embodiment, a nitride semiconductor element includes: a stacked body; and a functional layer. The stacked body includes a first GaN layer, a first layer, and a second GaN layer. The first GaN layer includes a first protrusion. The first layer is provided on the first GaN layer and contains at least one of Si and Mg. The second GaN layer is provided on the first layer and includes a second protrusion. Length of bottom of the second protrusion is shorter than length of bottom of the first protrusion. A functional layer is provided on the stacked body and includes a nitride semiconductor.

Abstract: According to one embodiment, a semiconductor light emitting device includes an n-type semiconductor layer, a p-type semiconductor layer, a light emitting portion, a first layer, a second layer, and an intermediate layer. The semiconductor layers include nitride semiconductor. The light emitting portion is provided between the n-type semiconductor layer and the p-type semiconductor layer and includes a quantum well layer. The first layer is provided between the light emitting portion and the p-type semiconductor layer and includes AlX1Ga1-x1N having first Al composition ratio x1. The second layer is provided between the first layer and the p-type semiconductor layer and includes Alx2Ga1-x2N having second Al composition ratio x2 higher than the first Al composition ratio x1. The intermediate layer is provided between the first layer and the light emitting portion and has a thickness not smaller than 3 nanometers and not larger than 8 nanometers and includes Inz1Ga1-z1N (0?z1<1).

Abstract: According to one embodiment, a semiconductor light emitting device includes a first semiconductor layer, a second semiconductor layer, a light emitting part, and a multilayered structural body. The light emitting part is provided between the first and second semiconductor layers and includes barrier layers and well layers alternately stacked. The multilayered structural body is provided between the first semiconductor layer and the light emitting part and includes high energy layers and low energy layers alternately stacked. An average In composition ratio on a side of the second semiconductor is higher than that on a side of the first semiconductor in the multilayered structural body. An average In composition ratio on a side of the second semiconductor is higher than that on a side of the first semiconductor in the light emitting part.

Abstract: According to one embodiment, a semiconductor light emitting device includes an n-type layer, a p-type layer, and a light emitting unit provided between the n-type layer and the p-type layer and including barrier layers and well layers. At least one of the barrier layers includes first and second portion layers. The first portion layer is disposed on a side of the n-type layer. The second portion layer is disposed on a side of the p-type layer, and contains n-type impurity with a concentration higher than that in the first portion layer. At least one of the well layers includes third and fourth portion layers. The third portion layer is disposed on a side of the n-type layer. The fourth portion layer is disposed on a side of the p-type layer, and contains n-type impurity with a concentration higher than that in the third portion layer.

Abstract: According to one embodiment, a semiconductor light emitting device includes a first semiconductor layer, a second semiconductor layer and a light emitting part. The first semiconductor layer includes an n-type semiconductor layer. The second semiconductor layer includes a p-type semiconductor layer. The light emitting part is provided between the first semiconductor layer and the second semiconductor layer, and includes a plurality of barrier layers and a well layer provided between the plurality of barrier layers. The first semiconductor layer has a first irregularity and a second irregularity. The first irregularity is provided on a first major surface of the first semiconductor layer on an opposite side to the light emitting part. The second irregularity is provided on a bottom face and a top face of the first irregularity, and has a level difference smaller than a level difference between the bottom face and the top face.

Abstract: According to one embodiment, a semiconductor light emitting device includes a first semiconductor layer of a first conductivity type and having a major surface, a second semiconductor layer of a second conductivity type, and a light emitting layer provided between the first and second semiconductor layers. The major surface is opposite to the light emitting layer. The first semiconductor layer has structural bodies provided in the major surface. The structural bodies are recess or protrusion. A centroid of a first structural body aligns with a centroid of a second structural body nearest the first structural. hb, rb, and Rb satisfy rb/(2·hb)?0.7, and rb/Rb<1, where hb is a depth of the recess, rb is a width of a bottom portion of the recess, and Rb is a width of the protrusion.

Abstract: According to one embodiment, a semiconductor light emitting device includes a first semiconductor layer, a second semiconductor layer, a light emitting part, and a multilayered structural body. The light emitting part is provided between the first and second semiconductor layers and includes barrier layers and well layers alternately stacked. The multilayered structural body is provided between the first semiconductor layer and the light emitting part and includes high energy layers and low energy layers alternately stacked. An average In composition ratio on a side of the second semiconductor is higher than that on a side of the first semiconductor in the multilayered structural body. An average In composition ratio on a side of the second semiconductor is higher than that on a side of the first semiconductor in the light emitting part.

Abstract: According to one embodiment, a semiconductor light emitting device includes an n-type layer, a p-type layer, and a light emitting unit provided between the n-type layer and the p-type layer and including barrier layers and well layers. At least one of the barrier layers includes first and second portion layers. The first portion layer is disposed on a side of the n-type layer. The second portion layer is disposed on a side of the p-type layer, and contains n-type impurity with a concentration higher than that in the first portion layer. At least one of the well layers includes third and fourth portion layers. The third portion layer is disposed on a side of the n-type layer. The fourth portion layer is disposed on a side of the p-type layer, and contains n-type impurity with a concentration higher than that in the third portion layer.

Abstract: According to an embodiment, a semiconductor light emitting device includes a foundation layer, a first semiconductor layer, a light emitting layer, and a second semiconductor layer. The foundation layer has an unevenness having recesses, side portions, and protrusions. A first major surface of the foundation layer has an overlay-region. The foundation layer has a plurality of dislocations including first dislocations whose one ends reaching the recess and second dislocations whose one ends reaching the protrusion. A proportion of a number of the second dislocations reaching the first major surface to a number of all of the second dislocations is smaller than a proportion of a number of the first dislocations reaching the first major surface to a number of all of the first dislocations. A number of the dislocations reaching the overlay-region of the first major surface is smaller than a number of all of the first dislocations.

Abstract: According to one embodiment, a semiconductor light emitting device includes a first semiconductor layer of a first conductivity type and having a major surface, a second semiconductor layer of a second conductivity type, and a light emitting layer provided between the first and second semiconductor layers. The major surface is opposite to the light emitting layer. The first semiconductor layer has structural bodies provided in the major surface. The structural bodies are recess or protrusion. A centroid of a first structural body aligns with a centroid of a second structural body nearest the first structural. hb, rb, and Rb satisfy rb/(2·hb)?0.7, and rb/Rb<1, where hb is a depth of the recess, rb is a width of a bottom portion of the recess, and Rb is a width of the protrusion.

Abstract: According to one embodiment, a vapor deposition method is disclosed for forming a nitride semiconductor layer on a substrate by supplying a group III source-material gas and a group V source-material gas. The method can deposit a first semiconductor layer including a nitride semiconductor having a compositional proportion of Al in group III elements of not less than 10 atomic percent by supplying the group III source-material gas from a first outlet and by supplying the group V source-material gas from a second outlet. The method can deposit a second semiconductor layer including a nitride semiconductor having a compositional proportion of Al in group III elements of less than 10 atomic percent by mixing the group III and group V source-material gases and supplying the mixed group III and group V source-material gases from at least one of the first outlet and the second outlet.

Abstract: According to one embodiment, a method is disclosed for manufacturing a nitride semiconductor device. The method can include removing a growth substrate from a structure body by using a first treatment material. The structure body has the growth substrate, a buffer layer formed on the growth substrate, and the nitride semiconductor layer formed on the buffer layer. A support substrate is bonded to the nitride semiconductor layer. The method can include reducing thicknesses of the buffer layer and the nitride semiconductor layer by using a second treatment material different from the first treatment material after removing the growth substrate.

Abstract: A crystal growth method for nitride semiconductors, including the steps of growing a first semiconductor layer containing InxGa1-xN (0<x?1) on a substrate, with the use of a first carrier gas formed with an inert gas; growing a second semiconductor layer containing InyGa1-yN (0?y<1, y<x) on the first semiconductor layer, with the use of a second carrier gas containing the inert gas and H2 gas, an amount of the H2 gas being smaller than an amount of the inert gas; and growing a third semiconductor layer containing InzGa1-zN (0?z<1, z<x) on the second semiconductor layer, with the use of a third carrier gas containing the inert gas and H2 gas, an amount of the H2 gas in the third carrier gas being a smaller than the amount of H2 gas in the second carrier gas.

Abstract: According to one embodiment, a semiconductor light-emitting device includes: a first conductivity type first semiconductor layer containing a nitride semiconductor crystal and having a tensile stress in a (0001) surface; a second conductivity type second semiconductor layer containing a nitride semiconductor crystal and having a tensile stress in the (0001) surface; a light emitting layer provided between the first semiconductor layer and the second semiconductor layer, containing a nitride semiconductor crystal, and having an average lattice constant larger than the lattice constant of the first semiconductor layer; and a first stress application layer provided on a side opposite to the light emitting layer of the first semiconductor layer and applying a compressive stress to the first semiconductor layer.

Abstract: According to one embodiment, a semiconductor light emitting device includes an electrode layer, a first semiconductor layer, a first elongated electrode, a second semiconductor layer, and a light emitting layer. The first semiconductor layer includes a crystal having a cleavage plane. The first semiconductor layer includes a first thin film portion and a thick film portion. The first thin film portion extends in a first direction perpendicular to a stacking direction from the electrode layer toward the first semiconductor layer. The first thin film portion has a first thickness. The thick film portion is arranged with the first thin film portion in a plane perpendicular to the stacking direction. An angle between the first direction and the cleavage plane is not less than 3 degrees and not more than 27 degrees. The first elongated electrode extends in the first direction in contact with the first thin film portion.

Abstract: According to one embodiment, a semiconductor light emitting device includes an n-type semiconductor layer, a p-type semiconductor layer, a light emitting part, and a p-side electrode. The light emitting part is provided between the n-type and the p-type semiconductor layers, and includes a plurality of barrier layers and a plurality of well layers. The p-side electrode contacts the p-type semiconductor layer. The p-type semiconductor layer includes first, second, third, and fourth p-type layers. The first p-type layer contacts the p-side electrode. The second p-type layer contacts the light emitting part. The third p-type layer is provided between the first p-type layer and the second p-type layer. The fourth p-type layer is provided between the second p-type layer and the third p-type layer. The second p-type layer contains Al and contains a p-type impurity in a lower concentration lower than that in the first concentration.