Semiconductor light-emitting device
View Patent ↗A semiconductor light-emitting device includes: a semiconductor chip having a growth surface that is a nonpolar or semipolar plane, and emitting polarized light; and a reflector having a reflective surface. At least part of light in a plane L 90 is reflected off the reflective surface in a direction of a normal line to the growth surface, and an amount of light reflected off the reflective surface in the plane L 90 in the direction of the normal line is larger than that of light reflected off the reflective surface on a plane L 45 in the direction of the normal line, where the plane L 90 represents a plane including the normal line and oriented at 90° to a polarization direction of the polarized light, and the plane L 45 represents a plane including the normal line, and oriented at 45° to the polarization direction of the polarized light.
1. A semiconductor light-emitting device comprising:
a semiconductor light-emitting chip having a growth surface that is a nonpolar or semipolar plane, and emitting polarized light; and
a reflection member having a reflective surface off which the polarized light is reflected, wherein
at least part of light in a plane L 90 is reflected off the reflective surface in a direction of a normal line to the growth surface, and an amount of light reflected off the reflective surface in the plane L 90 in the direction of the normal line to the growth surface is larger than an amount of light reflected off the reflective surface in a plane L 45 in the direction of the normal line to the growth surface, where the plane L 90 represents a plane including the normal line to the growth surface of the semiconductor light-emitting chip and oriented at an angle of 90° to a polarization direction of the polarized light, and the plane L 45 represents a plane including the normal line, and oriented at an angle of 45° to the polarization direction of the polarized light, and
Ry is higher than Rz, where Ry represents a reflectivity of a region of the reflective surface intersecting the plane L 90 , and Rz represents a reflectivity of a region of the reflective surface intersecting the plane L 45 .
2. The semiconductor light-emitting device of claim 1 , wherein
an arithmetic average inclination angle Δθ 1 z is larger than an arithmetic average inclination angle Δθ 1 y , where the arithmetic average inclination angle Δθ 1 y represents an angle between the reflective surface and the direction of the normal line to the growth surface of the semiconductor light-emitting chip when viewed in cross section taken along the plane L 90 , and the arithmetic average inclination angle Δθ 1 z represents an angle between the reflective surface and the direction of the normal line to the growth surface of the semiconductor light-emitting chip when viewed in cross section taken along the plane L 45 .
3. The semiconductor light-emitting device of claim 1 , wherein
the semiconductor light-emitting chip includes at least two semiconductor light-emitting chips, and
the at least two semiconductor light-emitting chips are arranged such that directions of polarization of light from the at least two semiconductor light-emitting chips are identical.
4. The semiconductor light-emitting device of claim 1 , wherein
the semiconductor light-emitting chip includes at least four semiconductor light-emitting chips,
the at least four semiconductor light-emitting chips are arranged in a matrix such that directions of polarization of light from the at least four semiconductor light-emitting chips are identical, and
D 2 is less than D 1 , where D 1 represents a distance between adjacent two of the at least four semiconductor light-emitting chips arranged in a direction perpendicular to the directions of polarization of the light, and D 2 represents a distance between adjacent two of the at least four semiconductor light-emitting chips arranged in a direction parallel to the directions of polarization of the light.
5. The semiconductor light-emitting device of claim 1 , further comprising:
a wavelength conversion member covering the semiconductor light-emitting chip.
6. The semiconductor light-emitting device of claim 1 , wherein
a linear reflectivity of the reflective surface is higher than a diffuse reflectivity of the reflective surface.
7. A semiconductor light-emitting device comprising:
a semiconductor light-emitting chip having a growth surface that is a nonpolar or semipolar plane, and emitting polarized light;
a reflection member having a reflective surface off which the polarized light is reflected, wherein
at least part of light in a plane L 90 is reflected off the reflective surface in a direction of a normal line to the growth surface, and an amount of light reflected off the reflective surface in the plane L 90 in the direction of the normal line to the growth surface is larger than an amount of light reflected off the reflective surface in a plane L 45 in the direction of the normal line to the growth surface, where the plane L 90 represents a plane including the normal line to the growth surface of the semiconductor light-emitting chip and oriented at an angle of 90° to a polarization direction of the polarized light, and the plane L 45 represents a plane including the normal line, and oriented at an angle of 45° to the polarization direction of the polarized light, and
Rz_d is higher than Ry_d, where Ry_d represents a diffuse reflectivity of a region of the reflective surface intersecting the plane L 90 , and Rz_d represents a diffuse reflectivity of a region of the reflective surface intersecting the plane L 45 .
8. The semiconductor light-emitting device of claim 7 , wherein
an arithmetic average inclination angle Δθ 1 z is larger than an arithmetic average inclination angle Δθ 1 y , where the arithmetic average inclination angle Δθ 1 y represents an angle between the reflective surface and the direction of the normal line to the growth surface of the semiconductor light-emitting chip when viewed in cross section taken along the plane L 90 , and the arithmetic average inclination angle Δθ 1 z represents an angle between the reflective surface and the direction of the normal line to the growth surface of the semiconductor light-emitting chip when viewed in cross section taken along the plane L 45 .
9. The semiconductor light-emitting device of claim 7 , wherein
the semiconductor light-emitting chip includes at least two semiconductor light-emitting chips, and
the at least two semiconductor light-emitting chips are arranged such that directions of polarization of light from the at least two semiconductor light-emitting chips are identical.
10. The semiconductor light-emitting device of claim 7 , wherein
the semiconductor light-emitting chip includes at least four semiconductor light-emitting chips,
the at least four semiconductor light-emitting chips are arranged in a matrix such that directions of polarization of light from the at least four semiconductor light-emitting chips are identical, and
D 2 is less than D 1 , where D 1 represents a distance between adjacent two of the at least four semiconductor light-emitting chips arranged in a direction perpendicular to the directions of polarization of the light, and D 2 represents a distance between adjacent two of the at least four semiconductor light-emitting chips arranged in a direction parallel to the directions of polarization of the light.
11. The semiconductor light-emitting device of claim 7 , further comprising:
a wavelength conversion member covering the semiconductor light-emitting chip.
12. The semiconductor light-emitting device of claim 7 , wherein
a linear reflectivity of the reflective surface is higher than a diffuse reflectivity of the reflective surface.
13. A semiconductor light-emitting device comprising:
a semiconductor light-emitting chip having a growth surface that is a nonpolar or semipolar plane, and emitting polarized light; and
a reflection member having a reflective surface off which the polarized light is reflected, wherein
at least part of light in a plane L 90 is reflected off the reflective surface in a direction of a normal line to the growth surface, and an amount of light reflected off the reflective surface in the plane L 90 in the direction of the normal line to the growth surface is larger than an amount of light reflected off the reflective surface in a plane L 45 in the direction of the normal line to the growth surface, where the plane L 90 represents a plane including the normal line to the growth surface of the semiconductor light-emitting chip and oriented at an angle of 90° to a polarization direction of the polarized light, and the plane L 45 represents a plane including the normal line, and oriented at an angle of 45° to the polarization direction of the polarized light,
the semiconductor light-emitting device further includes a light-transmissive member covering the semiconductor light-emitting chip, and
a region of the light-transmissive member intersecting the plane L 45 is made of a material having a higher diffuse transmittance than a region of the light-transmissive member intersecting the plane L 90 .
14. The semiconductor light-emitting device of claim 13 , wherein
an arithmetic average inclination angle Δθ 1 z is larger than an arithmetic average inclination angle Δθ 1 y , where the arithmetic average inclination angle Δθ 1 y represents an angle between the reflective surface and the direction of the normal line to the growth surface of the semiconductor light-emitting chip when viewed in cross section taken along the plane L 90 , and the arithmetic average inclination angle Δθ 1 z represents an angle between the reflective surface and the direction of the normal line to the growth surface of the semiconductor light-emitting chip when viewed in cross section taken along the plane L 45 .
15. The semiconductor light-emitting device of claim 13 , wherein
the semiconductor light-emitting chip includes at least two semiconductor light-emitting chips, and
the at least two semiconductor light-emitting chips are arranged such that directions of polarization of light from the at least two semiconductor light-emitting chips are identical.
16. The semiconductor light-emitting device of claim 13 , wherein
the semiconductor light-emitting chip includes at least four semiconductor light-emitting chips,
the at least four semiconductor light-emitting chips are arranged in a matrix such that directions of polarization of light from the at least four semiconductor light-emitting chips are identical, and
D 2 is less than D 1 , where D 1 represents a distance between adjacent two of the at least four semiconductor light-emitting chips arranged in a direction perpendicular to the directions of polarization of the light, and D 2 represents a distance between adjacent two of the at least four semiconductor light-emitting chips arranged in a direction parallel to the directions of polarization of the light.
17. The semiconductor light-emitting device of claim 13 , further comprising:
a wavelength conversion member covering the semiconductor light-emitting chip.
18. The semiconductor light-emitting device of claim 13 , wherein
a linear reflectivity of the reflective surface is higher than a diffuse reflectivity of the reflective surface.