SEMICONDUCTOR LIGHT-EMITTING ELEMENT AND LIGHT-EMITTING DEVICE USING THE SAME
A semiconductor light-emitting element includes: a substrate; a semiconductor stacked film including a first cladding layer of a first conductivity type formed on the substrate, a light-emitting layer formed on the first cladding layer, and a second cladding layer of a second conductivity type formed on the light-emitting layer, and having an optical waveguide; a first electrode formed so as to be electrically connected to the first cladding layer; and a second electrode formed so as to be electrically connected to the second cladding layer. The light-emitting layer generates guided light that is guided in the optical waveguide, and non-guided light that is not guided in the optical waveguide, and the non-guided light is emitted from one of the substrate side and the semiconductor stacked layer side to the outside.
1 . A semiconductor light-emitting element, comprising:
a substrate;
a semiconductor stacked film that includes a first cladding layer of a first conductivity type formed on the substrate, a light-emitting layer formed on the first cladding layer, and a second cladding layer of a second conductivity type formed on the light-emitting layer, and that has an optical waveguide;
a first electrode formed so as to be electrically connected to the first cladding layer; and
a second electrode formed so as to be electrically connected to the second cladding layer, wherein
the light-emitting layer generates guided light that is guided in the optical waveguide, and non-guided light that is not guided in the optical waveguide, and
the non-guided light is emitted from one of the substrate side and the semiconductor stacked layer side to outside.
2 . The semiconductor light-emitting element of clam 1 , wherein
the second electrode includes a transparent electrode comprised of a material that is transparent to the guided light and the non-guided light.
3 . The semiconductor light-emitting element of claim 2 , wherein
the second electrode includes a non-transparent electrode formed on a region of the transparent electrode other than the optical waveguide, and comprised of a material that is not transparent to the guided light and the non-guided light.
4 . The semiconductor light-emitting element of claim 1 , further comprising:
a reflecting portion formed below the light-emitting layer and configured to reflect the non-guided light.
5 . The semiconductor light-emitting element of claim 4 , wherein
the reflecting portion includes a reflecting film comprised of a metal and formed on a surface of the substrate which is located on an opposite side from a surface on which the semiconductor stacked film is formed.
6 . The semiconductor light-emitting element of claim 4 , wherein
the reflecting portion includes a film formed on the substrate and comprised of a material having a different refractive index from that of the semiconductor stacked film.
7 . The semiconductor light-emitting element of claim 4 , wherein
the reflecting portion includes a recess formed in an upper part of the substrate.
8 . The semiconductor light-emitting element of claim 1 , wherein
an end facet of the optical waveguide is tilted with respect to a direction perpendicular to a surface of the substrate.
9 . The semiconductor light-emitting element of claim 1 , wherein
the substrate is comprised of a material that is transparent to the guided light and the non-guided light.
10 . The semiconductor light-emitting element of claim 9 , wherein
the second electrode is comprised of a material that reflects the non-guided light.
11 . The semiconductor light-emitting element of claim 9 , wherein
the first electrode includes a non-transparent electrode comprised of a material that is not transparent to the guided light and the non-guided light, and
the non-transparent electrode has an opening below the optical waveguide.
12 . The semiconductor light-emitting element of claim 9 , wherein
the substrate includes a concavo-convex portion having a one-dimensional period or a two-dimensional period on its surface that is located on an opposite side from a surface on which the semiconductor stacked film is formed.
13 . The semiconductor light-emitting element of claim 9 , wherein
an end facet of the optical waveguide is tilted with respect to a direction perpendicular to a surface of the substrate.
14 . A light-emitting device, comprising:
the semiconductor light-emitting element of claim 1 ; and
a package configured to hold the semiconductor light-emitting element, wherein
the semiconductor light-emitting element is held such that its surface on the substrate side contacts the package, and
the guided light and the non-guided light which are emitted from the semiconductor light-emitting element are emitted from an upper side of the package to the outside.
15 . A light-emitting device, comprising:
the semiconductor light-emitting element of claim 1 ; and
a package configured to hold the semiconductor light-emitting element, wherein
the semiconductor light-emitting element is held such that its surface on the semiconductor stacked film side contacts the package, and
the guided light and the non-guided light which are emitted from the semiconductor light-emitting element are emitted from an upper side of the package to the outside.
16 . The light-emitting device of claim 14 , wherein
the package has a recessed shape having a bottom surface and a sidewall surface, and
the sidewall surface is tilted so as to form an obtuse angle with the bottom surface, and is configured to reflect the guided light.
17 . The light-emitting device of claim 14 , further comprising:
a member provided over the package and including a phosphor.
18 . The light-emitting device of claim 14 , wherein
the light-emitting device is configured to be selectable between a first operation of emitting the guided light and the non-guided light and a second operation of emitting only the non-guided light.
19 . The light-emitting device of claim 18 , wherein
the first operation is selected when an amount of current flowing in the semiconductor light-emitting element is larger than a threshold current, and
the second operation is selected when the amount of current flowing in the semiconductor light-emitting element is smaller than the threshold current.