Phosphor-converted LED devices having improved light distribution uniformity
View Patent ↗A New Phosphor-converted LED Device (“NPCLD”) is disclosed. The NPCLD may include a lens over a phosphor body, in which the lens and the phosphor body each have a substantially convex upper surface. The NPCLD may alternatively include first and second lenses, the first lens having a substantially flat interface with a phosphor body.
1. A New Phosphor-Converted LED Device (“NPCLD”) comprising:
a concave base housing;
a light emitting diode (“LED”) in the concave base housing, the LED having a p-doped semiconductor body and an n-doped semiconductor body;
a phosphor body over the LED, the phosphor body having a substantially convex upper surface;
a first lens over the phosphor body, the first lens having a substantially convex upper surface; and
a second lens interposed between the light emitting diode and the phosphor body, the second lens and the phosphor body together having a substantially flat interface.
2. The NPCLD of claim 1 , wherein the phosphor body includes a phosphor and an encapsulant, the phosphor substantially covering the LED.
3. The NPCLD of claim 1 , wherein:
the LED has an emission maximum within a range of about 420 nanometers to about 490 nanometers, the n-doped semiconductor body and the p-doped semiconductor body each include a member selected from the group consisting of gallium nitride, indium-gallium-nitride, gallium-aluminum-indium-nitride, and mixtures; and
the phosphor has an emission maximum within a range of about 550 nanometers to about 585 nanometers, the phosphor including a cerium-doped yttrium-aluminum garnet, further including
at least one element selected from the group consisting of yttrium, lutetium, selenium, lanthanum, gadolinium, samarium and terbium, and
at least one element selected from the group of aluminum, gallium and indium.
4. The NPCLD of claim 1 , further including:
a first terminal at a relatively high electrical potential in signal communication with the p-doped semiconductor body; and
a second terminal at a relatively low electrical potential in signal communication with the n-doped semiconductor body.
5. A method for fabricating a New Phosphor-Converted LED Device (“NPCLD”), the method comprising:
producing a concave base housing;
placing a light emitting diode (“LED”) in the concave base housing, the LED having a p-doped semiconductor body and an n-doped semiconductor body;
forming a phosphor body over the LED, the phosphor body having a substantially convex upper surface; and
forming a lens over the phosphor body, the lens having a substantially convex upper surface;
forming a second lens interposed between the light emitting diode and the phosphor body, the second lens and the phosphor body together having a substantially flat interface.
6. The method of claim 5 , further including substantially covering the LED with phosphor.
7. The method of claim 5 , wherein:
the LED has an emission maximum within a range of about 420 nanometers to about 490 nanometers, the n-doped semiconductor body and the p-doped semiconductor body each including a member selected from the group consisting of gallium nitride, indium-gallium-nitride, gallium-aluminum-indium-nitride, and mixtures; and
the phosphor has an emission maximum within a range of about 550 nanometers to about 585 nanometers, the phosphor including a cerium-doped yttrium-aluminum garnet, further including
at least one element selected from the group consisting of yttrium, lutetium, selenium, lanthanum, gadolinium, samarium and terbium; and
at least one element select from the group of aluminum, gallium and indium.