AC light emitting diode having improved transparent electrode structure
View Patent ↗Disclosed is an AC light emitting diode having an improved transparent electrode structure. The light emitting diode comprises a plurality of light emitting cells formed on a single substrate, each of the light emitting cells having a first conductive type semiconductor layer, a second conductive type semiconductor layer positioned on one region of the first conductive type semiconductor layer, and an active layer interposed between the first and second conductive type semiconductor layers. A transparent electrode structure is positioned on each of the light emitting cells. The transparent electrode structure includes at least two portions separated from each other, or a center portion and branches laterally extending from both sides of the center portion. Meanwhile, wires electrically connect adjacent two of the light emitting cells. Accordingly, a plurality of light emitting cells are electrically connected, whereby a light emitting diode can be provided which can be driven under AC power source. Also, an improved transparent electrode structure is employed, so that the current density can be prevented from being locally increased.
1. A light emitting diode (LED), comprising:
a plurality of light emitting cells formed on a single substrate, each of the light emitting cells comprising a first conductive type semiconductor layer, a second conductive type semiconductor layer positioned on a first region of the first conductive type semiconductor layer, and an active layer interposed between the first and second conductive type semiconductor layers;
a transparent electrode structure positioned on the second conductive type semiconductor layer of each of the light emitting cells, the transparent electrode structure comprising at least two portions completely separated from each other; and
wires electrically connecting adjacent two of the light emitting cells so that each of the at least two portions of the transparent electrode structure positioned on one of the adjacent two light emitting cells is electrically connected to the first conductive type semiconductor layer of other of the adjacent two light emitting cells,
wherein the at least two portions of the transparent electrode structure contact the second conductive type semiconductor layer positioned on the first region of the first conductive type semiconductor layer.
2. The LED as claimed in claim 1 , wherein each of the at least two portions of the transparent electrode structure comprises a shape elongated in a direction in which current flows between the light emitting cells.
3. The LED as claimed in claim 1 , further comprising:
an n-type electrode formed on a second region of the first conductive type semi-conductor layer in each of the light emitting cells; and
p-type electrode pads respectively formed on the at least two portions of the transparent electrode structure on each of the light emitting cells,
wherein the wires electrically connect the n-type electrodes and the p-type electrode pads.
4. A light emitting diode (LED), comprising:
a plurality of light emitting cells formed on a single substrate, each of the light emitting cells comprising a first conductive type semiconductor layer, a second conductive type semiconductor layer positioned on a first region of the first conductive type semiconductor layer, and an active layer interposed between the first and second conductive type semiconductor layers;
a transparent electrode structure positioned on each of the light emitting cells, the transparent electrode structure comprising a contiguous center portion having a plurality of branches extending from a first side of the center portion and a plurality of branches extending from a second side of the center portion; and
wires each electrically connecting adjacent two of the light emitting cells so that the transparent electrode structure positioned on one of the adjacent two light emitting cells is electrically connected to the first conductive type semiconductor layer of other of the adjacent two light emitting cells.
5. The LED as claimed in claim 4 , wherein the center portion comprises a shape elongated in a direction in which current flows between the light emitting cells, and the branches extend perpendicular to the direction in which the current flows.
6. The LED as claimed in claim 4 , further comprising:
an n-type electrode formed on a second region of the first conductive type semi-conductor layer in each of the light emitting cells; and
a p-type electrode pad formed on the center portion of the transparent electrode structure on each of the light emitting cells,
wherein each of the wires electrically connects the n-type electrode and the p-type electrode pad.
7. The LED of claim 1 , wherein the wires comprise a first wire connecting a first portion of the at least two portions of the transparent electrode and a second wire connecting a second portion of the at least two portions of the transparent electrode.