Display device using photonic crystal

• US 9,412,974 B2
• Filed: 06/21/2013
• Issued: 08/09/2016
• Est. Priority Date: 02/18/2013
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Mok, Rang-Kyun, Kim, Ki-Seo
• Primary Examiner(s): MENZ, DOUGLAS M
• Application Number:
  US13/924,509
• Publication Number:
  US 20140231758A1
• Time in Patent Office: 1,145 Days
• Field of Search: 257/40, 257/98
• US Class Current: 1/1
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H10K 50/30 Organic light-emitting transistors
• CPC Class Codes: H10K 50/856 comprising reflective means
• CPC Class Codes: H10K 59/878 comprising reflective means

Abstract

A display device including a light emitting transistor, and a photonic crystal on the light emitting transistor.

Claims

1. A display device comprising:

a light emitting transistor comprising a light emitting layer; and

a photonic crystal separate from the light emitting transistor, and being on the light emitting transistor,

wherein the photonic crystal has a plurality of patterns varying in size, based on a position of the light emitting layer,

wherein the light emitting transistor comprises;

a substrate;

a gate electrode on the substrate;

a gate insulating layer on the gate electrode;

a source electrode and a drain electrode spaced apart from the gate electrode by the gate insulating layer; and

the light emitting layer between the source electrode and the drain electrode, and

wherein a position of the light emitted in the light emitting layer varies as a function of a magnitude of a voltage applied to the gate electrode.

2. The display device of claim 1, wherein the light emitting layer comprises an organic material.

3. The display device of claim 1, wherein the light is emitted from a side of the light emitting layer adjacent the source electrode when substantially no voltage is applied to the gate electrode, and

wherein increasing a positive voltage applied to the gate electrode within a range of voltages causes a position of the emitted light to move closer to a side of the light emitting layer adjacent the drain electrode.

4. The display device of claim 3, wherein the source electrode comprises a cathode, and

wherein the drain electrode comprises an anode.

5. The display device of claim 1, wherein light emitted by the light emitting transistor is reflected by the photonic crystal.

6. The display device of claim 1, wherein the photonic crystal comprises a base part having the plurality of patterns.

7. The display device of claim 6, wherein a size of each of the patterns increases in a direction from one side of the base part to an opposite side of the base part.

8. The display device of claim 6, wherein each of the patterns comprises a concave groove shape.

9. The display device of claim 8, wherein a diameter of the concave groove shape is in a range from about 100 nm to about 300 nm.

10. The display device of claim 9, wherein the diameter of the concave groove shape increases in a direction from one side of the base part to an opposite side of the base part.

11. The display device of claim 9, wherein a depth of the concave groove shape is in a range from about 100 nm to about 200 nm.

15. The display device of claim 5, wherein the light reflected from the photonic crystal is displayed,

wherein the displayed light at a region adjacent a source electrode is a red-based light, and

wherein the displayed light at a region adjacent a drain electrode is a blue-based light.

16. The display device of claim 5, wherein the light reflected from the photonic crystal is displayed,

wherein the displayed light in a region adjacent a source electrode is a blue-based light, and

wherein the displayed light in a region adjacent a drain electrode is a red-based light.

12. A display device comprising:

a light emitting transistor comprising a light emitting layer; and

a photonic crystal separate from the light emitting transistor, and being on the light emitting transistor,

wherein the photonic crystal comprises a base part and a plurality of fine particles on the base part,

wherein the light emitting transistor comprises;

a substrate;

a gate electrode on the substrate;

a gate insulating layer on the gate electrode;

a source electrode and a drain electrode spaced apart from the gate electrode by the gate insulating layer; and

a light emitting layer between the source electrode and the drain electrode, and

wherein a position of the light emitted in the light emitting layer varies as a function of a magnitude of a voltage applied to the gate electrode.

13. The display device of claim 12, wherein a particle size of the fine particles is in a range from about 100 nm to about 300 nm.

14. The display device of claim 13, wherein the particle size of the fine particles increases in a direction from one side of the base part to an opposite side of the base part.

17. A display device comprising:

a light emitting transistor comprising;

a gate electrode;

a gate insulating layer on the gate electrode;

a source electrode and a drain electrode spaced apart from each other on the gate insulating layer; and

a light emitting layer between the source electrode and the drain electrode; and

a photonic crystal separate from the light emitting transistor, and being on the light emitting transistor,

wherein the photonic crystal has a plurality of patterns varying in size, based on a position of the light emitting layer, and

wherein the position of light emitted in the light emitting layer varies as a function of a voltage of the gate electrode.

18. The display device of claim 17, wherein the gate electrode comprises two or more gate electrodes spaced apart from each other.