PHOTOSENSOR AND DISPLAY DEVICE INCLUDING THE SAME

• US 20170084774A1
• Filed: 05/12/2016
• Published: 03/23/2017
• Est. Priority Date: 09/23/2015
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Im, Ki Ju, Kim, Min-Sung, Nguyen, Thanh Tien, Lee, Jae Seob
• Granted Patent: US 9,899,558 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 31/02327 the optical elements being integrated or being directly associated to the device, e.g. back reflectors optical coatings H01L31/0216
• CPC Class Codes: H01L 31/0296 including, apart from doping material or other impurities, only AIIBVI compounds, e.g. CdS, ZnS, HgCdTe
• CPC Class Codes: H01L 31/153 formed in, or on, a common substrate
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs

Abstract

A disclosed photosensor includes: a first electrode layer including a reflection part having an inclination surface; a first semiconductor layer positioned on the first electrode layer; a second electrode layer positioned on the first semiconductor layer; and a first dielectric layer and a second dielectric layer sequentially positioned on the second electrode layer, wherein the first dielectric layer and the second dielectric layer have different dielectric constant values. Further, the disclosed display device includes a plurality of pixel areas positioned on a substrate, and a sensor unit formed in at least some pixel areas among the plurality of pixel areas.

Claims

1. A photosensor comprising:

a first electrode layer including a reflection part having an inclination surface;

a first semiconductor layer positioned on the first electrode layer;

a second electrode layer positioned on the first semiconductor layer; and

a first dielectric layer and a second dielectric layer sequentially positioned on the second electrode layer,

wherein the first dielectric layer and the second dielectric layer have different dielectric constant values.

2. The photosensor of claim 1, wherein

the first dielectric layer has a first dielectric constant value and the second dielectric layer has a second dielectric constant value, and the first dielectric constant value is greater than the second dielectric constant value.

3. The photosensor of claim 2, wherein

difference of the first dielectric constant value and the second dielectric constant value is in a range of 3 to 60.

4. The photosensor of claim 2, wherein

the first dielectric constant value is in a range of 10 to 60.

5. The photosensor of claim 1, wherein

the first dielectric layer includes at least one selected from the group consisting of hafnium oxide (HfO₂), yttrium oxide (Y₂O₃), strontium oxide (SrO), barium oxide (BaO), titanium oxide (TiO), and combinations thereof.

6. The photosensor of claim 2, wherein

the second dielectric constant value is 10 or less.

7. The photosensor of claim 1, wherein

the second dielectric layer includes at least one selected from the group consisting of silicon dioxide (SiO₂), silicon nitride (Si₃N₄), and combinations thereof

8. The photosensor of claim 1, wherein

the reflection part includes protrusions and depressions.

9. The photosensor of claim 1, wherein

the second electrode layer includes at least one selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), and combinations thereof

10. The photosensor of claim 1, wherein

the first semiconductor layer includes at least one selected from the group consisting of a hydrogenated amorphous silicon, a polysilicon, and an oxide semiconductor.

11. The photosensor of claim 10, wherein

the oxide semiconductor includes at least one selected from the group consisting of oxides of gallium (Ga), indium (In), zinc (Zn), hafnium (Hf), and tin (Sn).

12. A display device comprising:

a plurality of pixel areas positioned on a substrate; and

a sensor unit formed in at least some pixel areas among the plurality of pixel areas,

wherein the sensor unit includes a photosensor which comprises;

a first electrode layer including a reflection part having an inclination surface;

a first semiconductor layer positioned on the first electrode layer;

a second electrode layer positioned on the first semiconductor layer; and

a first dielectric layer and a second dielectric layer sequentially positioned on the second electrode layer,

wherein the first dielectric layer and the second dielectric layer have different dielectric constant values.

13. The display device of claim 12, wherein

a pixel area of the plurality of pixel areas comprises:

a light emission part; and

a thin film transistor electrically connected to the light emission part,

wherein the thin film transistor comprises;

a second semiconductor layer, and

a source electrode and a drain electrode positioned on the second semiconductor layer, partially overlapping the second semiconductor layer, and separated from each other.

14. The display device of claim 13, wherein

the second semiconductor layer is an oxide semiconductor layer including at least one selected from the group consisting of oxides of gallium (Ga), indium (In), zinc (Zn), hafnium (Hf), and tin (Sn).

15. The display device of claim 14, wherein

the second semiconductor layer comprises indium-gallium-zinc oxide, and

the first semiconductor layer comprises hydrogenated amorphous silicon.

16. The display device of claim 13, wherein

the source electrode and the drain electrode are positioned at the same layer as the first electrode layer.

17. The display device of claim 12, wherein

the photosensor is a compensation sensor.

18. The display device of claim 12, wherein

the photosensor is a touch sensor.

19. The display device of claim 12, wherein

the first dielectric layer has a first dielectric constant value and the second dielectric layer has a second dielectric constant value, and the first dielectric constant value is greater than the second dielectric constant value.

20. The display device of claim 12, wherein

the reflection part includes protrusions and depressions.