Light emitting element and display device including the same

Patent metadata

Field	Value
Publication number	US-11710448-B2
Application number	US-202217578173-A
Country	US
Kind code	B2
Filing date	Jan 18, 2022
Priority date	Jan 18, 2021
Publication date	Jul 25, 2023
Grant date	Jul 25, 2023

Abstract

A light emitting element includes a first electrode, a second electrode, and a light emission layer interposed between the first electrode and the second electrode, where an emission efficiency of the light emission layer varies based on a voltage applied to at least one selected from the first electrode and the second electrode.

First claim

What is claimed is:

1. A light emitting element comprising:
a first electrode;
a second electrode; and
a light emission layer interposed between the first electrode and the second electrode,
wherein an emission efficiency of the light emission layer varies based on a voltage applied to at least one selected from the first electrode and the second electrode,
wherein a voltage applied to the first electrode in an emission period of one frame, during which the light emission layer emits light, is higher than a voltage applied to the second electrode in the emission period of the one frame, and
wherein a voltage applied to the second electrode in a non-emission period of the one frame, during which the light emission layer does not emit light, is higher than a voltage applied to the first electrode in the non-emission period of the one frame.

2. The light emitting element of claim 1 , wherein
the emission period in the one frame is longer than the non-emission period in the one frame.

3. The light emitting element of claim 1 , wherein
the emission efficiency of the light emission layer increases during the non-emission period in the one frame.

4. The light emitting element of claim 1 , wherein
the light emission layer includes a quantum dot layer.

5. The light emitting element of claim 4 , wherein
the quantum dot layer includes a quantum dot phosphor material or a phosphorescent material.

6. The light emitting element of claim 4 , wherein
the quantum dot layer is provided in plural.

7. A display device comprising
a plurality of pixels,
wherein each of the plurality of pixels includes:
a light emission diode;
a first transistor connected between an anode of the light emission diode and a first power source voltage line;
a second transistor which transmits a data signal to a gate of the first transistor in response to a first scan signal;
a capacitor connected to the gate of the first transistor, wherein the capacitor stores a voltage corresponding to the data signal;
a third transistor connected between one end of the first transistor and a cathode of the light emission diode;
a fourth transistor connected between the anode of the light emission diode and a second power source voltage line; and
a fifth transistor which complementarily operates with the fourth transistor and is connected between the cathode of the light emission diode and the second power source voltage line, and
wherein an emission efficiency of the light emission diode varies based on a voltage applied to at least one selected from the anode and the cathode.

8. The display device of claim 7 , wherein
the fifth transistor is turned on in an emission period, during which the light emission diode emits light, and
the third transistor and the fourth transistor are turned off in the emission period.

9. The display device of claim 8 , wherein
the fifth transistor is turned off in a non-emission period, during which the light emission diode does not emit light, and
the third transistor and the fourth transistor are turned on in the non-emission period.

10. The display device of claim 9 , wherein
a voltage applied to the anode during the emission period is higher than a voltage applied to the cathode during the emission period.

11. The display device of claim 10 , wherein
a voltage applied to the cathode during the non-emission period is higher than that applied to the anode during the non-emission period.

12. The display device of claim 9 , wherein
the emission period in one frame is longer than the non-emission period in the one frame.

13. The display device of claim 9 , wherein
an emission efficiency of a light emission layer of the light emission diode interposed between the anode and the cathode increases in the non-emission period.

14. The display device of claim 13 , wherein
the light emission layer includes a quantum dot layer.

15. The display device of claim 14 , wherein
the quantum dot layer includes a quantum dot phosphor material or a phosphorescent material.

16. The display device of claim 7 , wherein
the capacitor includes one electrode connected to the gate of the first transistor and another electrode connected to the first power source voltage line.

17. The display device of claim 7 , wherein
each of the plurality of pixels further includes:
a sixth transistor which is turned on during an emission period, during which the light emission diode emits light, and is connected between one end of the first transistor and the first power source voltage line; and
a seventh transistor which is turned on by the first scan signal and is connected between one end of the first transistor and the gate of the first transistor.

18. The display device of claim 17 , wherein
a level of the data signal is changed at least once during a non-emission period, during which the light emission diode does not emit light.

19. A light emitting element of a display device, the lighting emitting element comprising:
a first electrode;
a second electrode; and
a light emission layer interposed between the first electrode and the second electrode,
wherein a forward voltage is applied to the light emission layer during an emission period in one frame, during which the light emission layer emits light, and a reverse voltage is applied to the light emission layer during a non-emission period in the one frame, during which the light emission layer does not emit light.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Cho Oul
• Kim Tae Hyung
• Lee Ilyoung
• Jang Eun Joo
• Yoon Won Sik

Classifications

• H10H20/813

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

• H10H20/812

  within the light-emitting regions, e.g. having quantum confinement structures · CPC title

• H10H20/83 Primary

  Electrodes · CPC title

• H10K59/1213

  the pixel elements being TFTs · CPC title

• G09G3/32 Primary

  semiconductive, e.g. using light-emitting diodes [LED] · CPC title