Display device including nanostructured LEDs connected in parallel

Patent metadata

Field	Value
Publication number	US-11605758-B2
Application number	US-201916252144-A
Country	US
Kind code	B2
Filing date	Jan 18, 2019
Priority date	Jul 7, 2008
Publication date	Mar 14, 2023
Grant date	Mar 14, 2023

Abstract

The device according to the invention comprises a nanostructured LED with a first group of nanowires protruding from a first area of a substrate and a contacting means in a second area of the substrate. Each nanowire of the first group of nanowires comprises a p-i-n-junction and a top portion of each nanowire or at least one selection of nanowires is covered with a light-reflecting contact layer. The contacting means of the second area is in electrical contact with the bottom of the nanowires, the light-reflecting contact layer being in electrical contact with the contacting means of the second area via the p-i-n-junction. Thus when a voltage is applied between the contacting means of the second area and the light-reflecting contact layer, light is generated within the nanowire. On top of the light-reflecting contact layer, a first group of contact pads for flip-chip bonding can be provided, distributed and separated to equalize the voltage across the layer to reduce the average serial resistance.

First claim

The invention claimed is:

1. A light emitting diode (LED) display device comprising:
LED die comprising red LEDs, green LEDs, and blue LEDs each comprising a respective GaN buffer layer, and that each comprise pixels of a red-green-blue display device; and
a sub-mount comprising transistors for driving the pixels and contact pads attached to p-contact pads and n-contact pads of the LED die,
wherein:
the red LEDs are configured to emit red light through the buffer layer upon application of voltage thereto, the red LEDs comprise a gallium nitride or an indium gallium nitride layer;
the green LEDs are configured to emit green light through the buffer layer upon application of voltage thereto;
the blue LEDs are configured to emit blue light through the buffer layer upon application of voltage thereto;
the red LEDs, the green LEDs and the blue LEDs comprise a semiconductor material core of a first conductivity type, a semiconductor material active region located radially outward of the semiconductor material core, and a semiconductor material shell of a second conductivity type located radially outward of the semiconductor material active region; and
the red LEDs, the green LEDs and the blue LEDs comprise a plurality of contact groups of red LEDs, green LEDs and blue LEDs, respectively, wherein each of the red LEDs, the green LEDs and the blue LEDs within a contact group are electrically connected in parallel, and the plurality of contact groups of red LEDs, green LEDs and blue LEDs are arranged in a two-dimensional array on the sub-mount and each contact group of red LEDs, green LEDs and blue LEDs is individually and exclusively addressable based on a column and row location of the respective contact group within the two-dimensional array.

2. The LED display device of claim 1 , wherein the red LEDs, the green LEDs and the blue LEDs comprise nanowires.

3. The LED display of claim 2 , further comprising an electrically conductive material that extends down the sidewalls of at least a portion of the nanowires of the red LEDs, the green LEDs and the blue LEDs.

4. The LED display device of claim 1 , wherein the red LEDs, the green LEDs and the blue LEDs comprise pn or p-i-n junctions.

5. The LED display device of claim 1 , wherein the gallium nitride or the indium gallium nitride layer in the red LEDs comprises the GaN buffer layer.

6. The LED display device of claim 1 , wherein the red LEDs comprise an active layer which is the indium gallium nitride layer.

7. The LED display device of claim 1 , further comprising a transparent contact layer or a light-reflecting layer covering at least a portion of the red LEDs, the green LEDs and the blue LEDs.

8. The LED display device of claim 1 , wherein each of the red LEDs, the green LEDs and the blue LEDs within the contact group are electrically connected in parallel via a first contact pad to a same row line and a same column line, and are electrically connected via a second contact pad to a common contact of a plurality of contact groups.

Assignees

• Glo Ab
• Nanosys Inc

Inventors

• Konsek Steven
• Ohlsson Jonas
• Martynov Yourii
• Hanberg Peter Jesper

Classifications

• H10H20/8316

  Multi-layer electrodes comprising at least one discontinuous layer · CPC title

• H10H20/813 Primary

  having a plurality of light-emitting regions, e.g. multi-junction LEDs or light-emitting devices having photoluminescent regions within the bodies · CPC title

• B82B1/00

  Nanostructures formed by manipulation of individual atoms or molecules, or limited collections of atoms or molecules as discrete units · CPC title

• H10H20/811 Primary

  having quantum effect structures or superlattices, e.g. tunnel junctions · CPC title

• H10H29/142

  Two-dimensional arrangements, e.g. asymmetric LED layout · CPC title