Quantum dot containers for micro-LED displays
A color micro-LED display chip includes light-emitting diodes (LEDs) and quantum dot (QD) containers that contain quantum dots. The QD containers are positioned to receive light emitted from the LEDs. The QD containers are shaped to have an entrance face, an opposing exit face and a waist located between the two faces. The waist has an area that is less than an area of one of the faces and less than or equal to an area of the other face.
1 . A color micro-LED display chip comprising:
a plurality of light-emitting diodes (LEDs); and
a plurality of quantum dot (QD) containers positioned to receive light emitted from the plurality of LEDs, the plurality of QD containers shaped to have two faces and a waist located between the two faces, the two faces comprising an entrance face and an exit face opposing the entrance face, the waist having a cross-sectional area that is less than a cross-sectional area of a first face of the two faces and less than or equal to a cross-sectional area of a second face of the two faces.
2 . The color micro-LED display chip of claim 1 wherein the cross-sectional area of the waist is less than the cross-sectional area of the first face and equal to the cross-sectional area of the second face.
3 . The color micro-LED display chip of claim 2 wherein the cross-sectional area of the waist is less than the cross-sectional area of the exit face and equal to the cross-sectional area of the entrance face.
4 . The color micro-LED display chip of claim 2 wherein the plurality of QD containers have a constant cross-sectional area between the waist and the face with the equal cross-sectional area.
5 . The color micro-LED display chip of claim 1 wherein, for each face with cross-sectional area greater than the cross-sectional area of the waist, the plurality of QD containers have a monotonically increasing cross-sectional area from the waist to the face with cross-sectional area greater than the cross-sectional area of the waist.
6 . The color micro-LED display chip of claim 5 wherein, for each face with cross-sectional area greater than the cross-sectional area of the waist, the plurality of QD containers have straight, tapered sidewalls between the waist and the face with cross-sectional area greater than the cross-sectional area of the waist.
7 . The color micro-LED display chip of claim 1 wherein the entrance face, waist and exit face all have a same shape.
8 . The color micro-LED display chip of claim 7 wherein all cross sections of the plurality of QD containers along a length of the plurality of QD containers have the same shape.
9 . The color micro-LED display chip of claim 1 wherein the plurality of QD containers are axially symmetric with circular cross-section.
10 . The color micro-LED display chip of claim 9 wherein a diameter of the circular cross-section is constant from the entrance face to the waist, and then increasing from the waist to the exit face.
11 . The color micro-LED display chip of claim 9 wherein a diameter of the circular cross-section is decreasing from the entrance face to the waist, and then increasing from the waist to the exit face.
12 . The color micro-LED display chip of claim 1 further comprising: quantum dots contained in the plurality of QD containers, the quantum dots converting light from the plurality of LEDs to a different color.
13 . The color micro-LED display chip of claim 12 wherein the plurality of QD containers are only partly filled with quantum dots.
14 . The color micro-LED display chip of claim 1 wherein the entrance faces of the plurality of QD containers abut the plurality of LEDs emitting light into the plurality of QD containers.
15 . The color micro-LED display chip of claim 1 wherein the plurality of LEDs and the plurality of QD containers are supported by a single substrate.
16 . The color micro-LED display chip of claim 1 wherein the plurality of LEDs and the plurality of QD containers are two stacked layers.
17 . A color micro-LED display chip comprising:
a plurality of light-emitting diodes (LEDs); and
a plurality of quantum dot (QD) containers positioned to receive light emitted from the plurality of LEDs, the plurality of QD containers shaped to have two faces and a waist located between the two faces, the two faces comprising an entrance face and an exit face opposing the entrance face, where an area of the waist is less than an area of either of the two faces.
18 . A color micro-LED display comprising:
a plurality of light emitters of different colors arranged into individually addressable color pixels, the plurality of light emitters comprising:
light-emitting diodes (LEDs);
quantum dot (QD) containers positioned to receive light emitted from the LEDs, the QD containers shaped to have two faces and a waist located between the two faces, the two faces comprising an entrance face and an exit face opposing the entrance face, the waist having an area that is less than an area of a first face of the two faces and less than or equal to an area of a second face of the two faces; and
quantum dots contained in the QD containers, the quantum dots converting light received from the LEDs to a different color; and
CMOS driver circuits that receive digital signals representing the color pixels to be displayed, the CMOS driver circuits driving the LEDs according to the digital signals; and
microlenses positioned to collect light from the QD containers.
19 . The color micro-LED display of claim 18 wherein the LEDs all emit light of a same color, and the quantum dots convert light from the LEDs to other colors in the color pixels.
20 . The color micro-LED display of claim 18 wherein the color micro-LED display produces light for a system characterized by an acceptance cone, and the plurality of light emitters couple more light into the acceptance cone compared to the plurality of light emitters with QD containers without waists.