Granted Patent B2

US 10,418,499 · App. 15/610,968 · Granted Sep 17, 2019

Inventors: Richard P. Schneider (Albuquerque, NM); Benjamin Leung (Sunnyvale, CA)

Assignee: GLO AB

H01L31/035227H01L27/124H01L27/14607H01L27/153H01L33/06H01L33/18H01L33/40

Abstract

Claims (36)

1. A light emitting device, comprising:

a substrate including a doped compound semiconductor layer;

a growth mask layer located on a top surface of the doped compound semiconductor layer;

a plurality of clusters of semiconductor structures extending from the top surface of the doped compound semiconductor layer, wherein the plurality of clusters are separated by inter-cluster regions that lack semiconductor structures, and wherein each semiconductor structure comprises a core of a first conductivity type extending through a respective opening through the growth mask layer, and an active light emitting shell; and

a second conductivity type semiconductor material layer located within each cluster of semiconductor structures and contacting sidewalls of each semiconductor structure within each cluster of semiconductor structures;

a conductive reflector that is electrically shorted to the second conductivity type semiconductor material layer and including tapered sidewalls that are parallel to a respective one of the faceted sidewalls of the second conductivity type semiconductor material layer;

a dielectric material layer including inner sidewalls that contact a respective one of the faceted sidewalls of the second conductivity type semiconductor material layer and outer sidewalls that contact inner tapered sidewalls of the conductive reflector;

a conductive bonding structure overlying, and contacting, the conductive reflector, and comprising a solder material; and

a transparent conductive oxide layer located on top of the second conductivity type semiconductor material layer and contacting a bottom surface of the conductive reflector;

wherein faceted sidewalls of the second conductivity type semiconductor material layer adjoin a top surface of the growth mask layer around a periphery of the second conductivity type semiconductor material layer;

wherein the faceted sidewalls of the second conductivity type semiconductor material layer include crystallographic p-planes; and

wherein the semiconductor structures comprise semiconductor nanowires, and the core comprises a nanowire core.

2. The light emitting device of claim 1 , wherein each cluster of semiconductor nanowires and a portion of the second conductivity type semiconductor material layer in each cluster comprises a light emitting diode (LED) which has a length of 1 to 5 microns parallel to the top surface of the doped compound semiconductor layer.

3. A direct view display device, comprising:

a plurality of LEDs of claim 2 ; and

a backplane comprising metal interconnect structures therein or thereupon;

wherein:

each LED is electrically connected to a respective one of the metal interconnect structures and constitutes a first subpixel which emits light at a first peak wavelength of a respective pixel of the direct view display device;

the first sub-pixel is separated from adjacent subpixels on the substrate by the inter-cluster regions;

the openings in the growth mask layer correspond to locations of the clusters of semiconductor nanostructures; and

the inter-cluster regions lack the openings in the growth mask layer.

4. The direct view display device of claim 3 , wherein the respective pixel further comprises:

a second subpixel comprising a second LED which emits light at a second peak wavelength different from the first peak wavelength; and

a third subpixel comprising a third LED which emits light at a third peak wavelength different from the first and the second peak wavelengths.

5. The light emitting device of claim 1 , wherein:

the second conductivity type semiconductor material layer is a continuous material layer within each cluster of semiconductor nanowires and contacts all outer surfaces of the active light emitting shells within each cluster of semiconductor nanowires;

the second conductivity type semiconductor material layer is discontinuous between the clusters of semiconductor nanowires and is not present in the inter-cluster region; and

wherein the outer surfaces of the active light emitting shells comprises:

vertical m-plane faceted surfaces that extend perpendicular to the top surface of the doped compound semiconductor layer; and

tapered p-plane faceted surfaces located at a tip of each semiconductor nanowire and adjoined to an upper edge of a respective one of the vertical m-plane faceted surfaces.

6. The light emitting device of claim 1 , wherein each of the faceted sidewalls of the second conductivity type semiconductor material layer that adjoins the top surface of the growth mask layer is at a same angle with respect a plane including the top surface of the growth mask layer.

7. The light emitting device of claim 1 , wherein:

each of the faceted sidewalls of the second conductivity type semiconductor material layer extends within a respective two-dimensional plane from the top surface of the growth mask layer to a location overlying a tip of a respective outermost semiconductor nanowire within the cluster of semiconductor nanowires; and

the faceted sidewalls of the second conductivity type semiconductor material layer at a periphery of each cluster consist of crystallographic p-planes.

8. The light emitting device of claim 1 , wherein the second conductivity type semiconductor material layer comprises vertical seams at locations that are equidistant from outer sidewalls of a neighboring pair of active light emitting shells.

9. The light emitting device of claim 8 , wherein the second conductivity type semiconductor material layer embeds cavities below the vertical seams between neighboring pairs of semiconductor nanowires in the clusters of semiconductor nanowires.

Assignments (10)

Cited By (1)

US 12,369,430