Light-emitting device using oxide semiconductor thin-film transistor and image display apparatus using the same

• US 7,696,513 B2
• Filed: 03/02/2007
• Issued: 04/13/2010
• Est. Priority Date: 03/17/2006
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Hayashi, Ryo, Iwasaki, Tatsuya
• Primary Examiner(s): Gurley; Lynne A
• Assistant Examiner(s): Gebreyesus; Yosef
• Application Number:
  US12/282,721
• Publication Number:
  US 20090072233A1
• Time in Patent Office: 1,138 Days
• Field of Search: 257/40, 257/43, 257/59, 257/72, 257/79, 257/83, 257/103, 257/E39.007, 257/E51.001, 257/E51.003, 257/E51.008, 257/88, 257 89-100, 438/70, 313/491, 345/76, 345/87
• US Class Current: 257/43
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H10K 2102/3031 Two-side emission, e.g. transparent OLEDs [TOLED]
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/121 characterised by the geometry or disposition of pixel elements
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels

Abstract

The present invention provides a light-emitting device, including: a pixel region provided on a substrate and including a blue pixel region, a green pixel region, and a red pixel region which correspond to lights of three primary colors of blue, green and red light, respectively, the pixel region including: a thin-film transistor having a source electrode, a drain electrode, a gate electrode, a gate insulating film, and an active layer; a light-emitting layer; and a lower electrode and a counter electrode for sandwiching the light-emitting layer therebetween, wherein the active layer includes an oxide; the drain electrode is electrically connected with a part of the light-emitting layer; and the thin-film transistor is arranged in a region other than the blue pixel region on the substrate.

Claims

1. A light-emitting device, comprising:

a pixel region provided on a substrate and including a blue pixel region, a green pixel region, and a red pixel region which correspond to lights of three primary colors of blue, green and red, respectively, the pixel region including;

a thin-film transistor having a source electrode, a drain electrode, a gate electrode, a gate insulating film, and an active layer;

a light-emitting layer; and

a lower electrode and a counter electrode for sandwiching the light-emitting layer therebetween,

wherein the active layer includes an oxide;

the drain electrode is electrically connected with a part of the light-emitting layer;

the thin-film transistor is arranged in the pixel region other than the blue pixel region on the substrate and is provided in at least one of the green pixel region and the red pixel region; and

the thin-film transistor is provided with no light-shielding film.

2. A light-emitting device according to claim 1, wherein the active layer comprises an oxide having a transmittance of 70% or more to light having a wavelength range of 400 nm to 800 nm.

3. A light-emitting device according to claim 1, wherein the oxide of the active layer contains In, Ga, and Zn, and has an electron carrier concentration smaller than 10¹⁸/cm³, and at least a part of the oxide is an amorphous oxide.

4. A light-emitting device according to claim 1, wherein at least one of the source electrode, the drain electrode, and the gate electrode comprises a transparent conductive oxide.

5. A light-emitting device according to claim 1, wherein the lower electrode comprises a transparent conductive oxide.

6. A light-emitting device according to claim 1, wherein at least one of the source electrode, the drain electrode, the gate electrode, and the lower electrode contains In, Ga, and Zn, and has an electron carrier concentration of 10¹⁸/cm³ or more, and at least a part of the oxide is an amorphous oxide.

7. A light-emitting device according to claim 1, wherein the light-emitting layer comprises an organic EL element.

8. An image display apparatus, comprising the light-emitting device according to claim 1.