Light-emitting device
View Patent ↗An object of the present invention is to provide a new light-emitting device with the use of an amorphous oxide. The light-emitting device has a light-emitting layer existing between first and second electrodes and a field effect transistor, of which the active layer is an amorphous.
1. A light-emitting device having a light-emitting element comprising first and second electrodes and a light-emitting layer existing between the first and second electrodes, and a field effect transistor for driving the light-emitting element, wherein an active layer of the field effect transistor comprises an amorphous oxide of a compound having
(a) a composition when in crystalline state represented by In 2−x M3 x O 3 (Zn 1−y M2 y O) m , wherein M2 is Mg or Ca; M3 is B, Al, Ga or Y; 0≦x≦2; 0≦y≦1; and m is zero or a natural number less than 6, or a mixture of said compounds;
(b) an electron carrier concentration of greater than 10 12 /cm 3 and lesser than 10 18 /cm 3 wherein a current between a drain terminal and a source terminal of the field effect transistor when no gate voltage is applied is less than 10 microamperes; and
(c) oxygen defect density decreased by treatment in an atmosphere including oxygen at a predetermined pressure during or after formation of the active layer of the amorphous oxide.
2. The light-emitting device according to claim 1 , wherein the amorphous oxide includes at least one of In, Zn and Sn.
3. The light-emitting device according to claim 1 , wherein the amorphous oxide is any one selected from the group consisting of an oxide containing In, Zn, and Sn; an oxide containing In and Zn; an oxide containing In and Sn; and an oxide containing In.
4. The light-emitting device according to claim 1 , wherein the amorphous oxide includes In, Zn and Ga.
5. The light-emitting device according to claim 1 , wherein the light-emitting element and the field effect transistor are arranged on an optically transparent substrate, and a light emitted from the light-emitting layer is output through the substrate.
6. The light-emitting device according to claim 5 , wherein the field effect transistor is arranged between the substrate and the light-emitting layer.
7. The light-emitting device according to claim 1 , wherein the light-emitting element and the field effect transistor are arranged on an optically transparent substrate, and a light emitted from the light-emitting layer is output through the substrate and the amorphous oxide.
8. The light-emitting device according to claim 7 , wherein the field effect transistor is arranged between the substrate and the light-emitting layer.
9. The light-emitting device according to claim 1 , wherein at least one of the drain electrode of the field effect transistor and the second electrode is formed of an optically transparent electroconductive oxide.
10. The light-emitting device according to claim 1 , wherein the light-emitting element is an electroluminescent element.
11. The light-emitting device according to claim 1 , wherein a plurality of the light-emitting elements are arranged at least in a single row.
12. The light-emitting device according to claim 11 , wherein the light-emitting element is arranged so as to be adjacent to the field effect transistor.
13. An electrophotographic device having
a photoreceptor,
an electrifier for electrifying the photoreceptor,
an exposing light source for exposing the photoreceptor in order to form a latent image on the photoreceptor, and
a developing unit for developing the latent image, wherein
the exposing light source has the light-emitting device according to claim 11 .
14. The electrophotographic device according to claim 13 , wherein the amorphous oxide contains a group-IV element M4, wherein M4 is selected from the group consisting of Sn, Si, Ge, and Zr.
15. The light-emitting device according to claim 1 , wherein the amorphous oxide contains a group-IV element M4, wherein M4 is selected from the group consisting of Sn, Si, Ge, and Zr.
16. The light-emitting device according to claim 1 , wherein the amorphous oxide is an oxide which exhibits a halo pattern and no characteristic diffraction line in an x-ray diffraction spectrogram.
17. The light-emitting device according to claim 1 , wherein the amorphous oxide has an electronic carrier concentration of less than 10 16 /cm 3 .
18. The light-emitting device according to claim 1 , wherein an electron mobility of the amorphous oxide increases when the electron carrier concentration increases.
19. A light-emitting device having a light-emitting element comprising first and second electrodes and a light-emitting layer existing between the first and second electrodes, and a field effect transistor for driving the light-emitting element, wherein an active layer of the field effect transistor comprises a transparent amorphous-oxide semiconductor having
(a) a composition when in crystalline state represented by In 2−x M3 x O 3 (Zn 1−y M2 y O) m , wherein M2 is Mg or Ca; M3 is B, Al, Ga or Y; 0≦x≦2; 0≦y≦1; and m is zero or a natural number less than 6, or a mixture of said compounds;
(b) an electron carrier concentration of greater than 10 12 /cm 3 and lesser than 10 18 /cm 3 , wherein the amorphous oxide semiconductor is capable of realizing a normally off state such that a current between a drain terminal and a source terminal of the field effect transistor when no gate voltage is applied is less than 10 microamperes; and
(c) oxygen defect density decreased by treatment in an atmosphere including oxygen at a predetermined pressure during or after formation of the active layer of the amorphous oxide.
20. The light-emitting device according to claim 1 or 18 , wherein the light-emitting element and the field effect transistor are layered.
21. The light-emitting device according to claim 19 , wherein the amorphous oxide contains a group-IV element M4, wherein M4 is selected from the group consisting of Sn, Si, Ge, and Zr.
22. The light-emitting device according to claim 19 , wherein the amorphous oxide is an oxide which exhibits a halo pattern and no characteristic diffraction line in an x-ray diffraction spectrogram.
23. The light-emitting device according to claim 19 , wherein the amorphous oxide has an electron carrier concentration of less than 10 16 /cm 3 .
24. The light-emitting device according to claim 19 , wherein an electron mobility of the amorphous oxide increases when the electron carrier concentration increases.
25. An active matrix display device comprising pixel circuits arranged into a two-dimensional matrix form, each of the pixel circuits comprising:
a light-emitting element comprising first and second electrodes and a light-emitting layer existing between the first and second electrodes; and
a field effect transistor for driving the light-emitting element, wherein an active layer of the field effect transistor includes such a transparent amorphous-oxide semiconductor having
(a) a composition when in crystalline state represented by In 2−x M3 x O 3 (Zn 1−y M2 y O) m , wherein M2 is Mg or Ca; M3 is B, Al, Ga or Y; 0≦x≦2; 0≦y≦1; and m is zero or a natural number less than 6, or a mixture of said compounds;
(b) an electron carrier concentration of greater than 10 12 /cm 3 and lesser than 10 18 /cm 3 , wherein the amorphous oxide semiconductor is capable of realizing a normally off state such that a current between a drain terminal and a source terminal of the field effect transistor when no gate voltage is applied is less than 10 microamperes; and
(c) oxygen defect density decreased by treatment in an atmosphere including oxygen at a predetermined pressure during or after formation of the active layer of the amorphous oxide.
26. The active matrix display device according to claim 23 , wherein the light-emitting element and the field effect transistor are layered.
27. The active matrix display device according to claim 25 , wherein the amorphous oxide contains a group-IV element M4, wherein M4 is selected from the group consisting of Sn, Si, Ge, and Zr.
28. The active matrix display device according to claim 25 , wherein the amorphous oxide is an oxide which exhibits a halo pattern and no characteristic diffraction line in an x-ray diffraction spectrogram.
29. The active matrix display device according to claim 25 , wherein the amorphous oxide has an electron carrier concentration of less than 10 16 /cm 3 .
30. The light-emitting device according to claim 25 , wherein an electron mobility of the amorphous oxide increases when the electron carrier concentration increases.
31. A display article comprising:
a light-emitting element comprising first and second electrodes and a light-emitting layer existing between the first and second electrodes and a field effect transistor for driving the light-emitting element, wherein an active layer of the field effect transistor includes an amorphous oxide semiconductor having
(a) a composition when in crystalline state represented by In 2−x M3 x O 3 (Zn 1−y M2 y O) m , wherein M2 is Mg or Ca; M3 is B, Al, Ga or Y; 0≦x≦2; 0≦y≦1; and m is zero or a natural number less than 6 , or a mixture of said compounds;
(b) an electron carrier concentration of greater than 10 12 /cm 3 and lesser than 10 18 /cm 3 , wherein a current between a drain terminal and a source terminal of the field effect transistor when no gate voltage is applied is less than 10 microamperes; and
(c) oxygen defect density decreased by treatment in an atmosphere including oxygen at a predetermined pressure during or after formation of the active layer of the amorphous oxide.
32. The display article according to claim 31 , wherein the amorphous oxide is any one selected from the group consisting of an oxide containing In, Zn and Sn; an oxide containing In and Zn; and oxide containing In and Sn; and an oxide containing In.
33. The display article according to claim 31 , wherein the transistor is a normally-off type transistor.
34. The display article according to claim 31 , wherein the light-emitting element and the field effect transistor are layered.
35. The display article according to claim 31 , wherein the amorphous oxide contains a group-IV element M 4 , wherein M 4 is selected from the group consisting of Sn, Si, Ge, and Zr.
36. The display article according to claim 31 , wherein the amorphous oxide is an oxide which exhibits a halo pattern and no characteristic diffraction line in an x-ray diffraction spectrogram.
37. The display article according to claim 31 , wherein the amorphous oxide has an electron carrier concentration of less than 10 16 /cm 3 . line in an x-ray diffraction spectrogram.
38. The light-emitting device according to claim 31 , wherein an electron mobility of the amorphous oxide increases when the electron carrier concentration increases.
39. A light-emitting device having a light-emitting element comprising first and second electrodes and a light-emitting layer existing between the first and second electrodes, and a field effect transistor for driving the light-emitting element, wherein an active layer of the field effect transistor comprises an amorphous-oxide of a compound having
(a) a composition selected from an oxide containing In, Ga, and Zn, an oxide containing In, Zn, and Sn, an oxide containing In and Sn, and an oxide containing In;
(b) an electron carrier concentration of greater than 10 12 /cm 3 and lesser than 10 18 /cm 3 wherein a current between a drain terminal and a source terminal of the field effect transistor when no gate voltage is applied is less than 10 microamperes; and
(c) an oxygen defect density decreased by treatment in an atmosphere including oxygen at a predetermined pressure during or after formation of the active layer of the amorphous oxide.
40. The light-emitting device according to claim 39 , wherein the amorphous oxide is an oxide which exhibits a halo pattern and no characteristic diffraction line in an x-ray diffraction spectrogram.
41. The light-emitting device according to claim 39 , wherein the amorphous oxide has an electron carrier concentration of less than 10 16 /cm 3 .
42. The light-emitting device according to claim 39 , wherein an electron mobility of the amorphous oxide increases when the electron carrier concentration increases.
43. A display article comprising:
a light-emitting element comprising first and second electrodes and a light-emitting layer existing between the first and second electrodes and a field effect transistor for driving the light-emitting element, wherein an active layer of the field effect transistor comprises an amorphous oxide of a compound having
(a) a composition selected from an oxide containing In, Ga, and Zn, an oxide containing In, Zn, and Sn, an oxide containing In and Sn, and an oxide containing In;
(b) an electron carrier concentration of greater than 10 12 /cm 3 and lesser than 10 18 /cm 3 , wherein a current between a drain terminal and a source terminal of the field effect transistor when no gate voltage is applied is less than 10 microamperes; and
(c) an oxygen defect density decreased by treatment in an atmosphere including oxygen at a predetermined pressure during or after formation of the active layer of the amorphous oxide.
44. The display article according to claim 43 , wherein the amorphous oxide is an oxide which exhibits a halo pattern and no characteristic diffraction line in an x-ray diffraction spectrogram.
45. The display article according to claim 43 , wherein the amorphous oxide has an electron carrier concentration of less than 10 16 /cm 3 .
46. The light-emitting device according to claim 43 , wherein an electron mobility of the amorphous oxide increases when the electron carrier concentration increases.
47. A light-emitting device having a light-emitting element comprising first and second electrodes and a light-emitting layer existing between the first and second electrodes, and a field effect transistor for driving the light-emitting element, wherein an active layer of the field effect transistor comprises an amorphous oxide of a compound having
(a) a composition selected from an oxide containing In, Ga, and Zn, an oxide containing In, Zn, and Sn, an oxide containing In and Sn, and an oxide containing In;
(b) an electron carrier concentration of greater than 10 12 /cm 3 and lesser than 10 18 /cm 3 , wherein the amorphous oxide semiconductor is capable of realizing a normally off state such that a current between a drain terminal and a source terminal of the field effect transistor when no gate voltage is applied is less than 10 microamperes; and
(c) an oxygen defect density decreased by treatment in an atmosphere including oxygen at a predetermined pressure during or after formation of the active layer of the amorphous oxide.
48. The light-emitting device according to claim 47 , wherein the amorphous oxide is an oxide which exhibits a halo pattern and no characteristic diffraction line in an x-ray diffraction spectrogram.
49. The light-emitting device according to claim 47 , wherein the amorphous oxide has an electron carrier concentration of less than 10 16 /cm 3 .
50. The light-emitting device according to claim 47 , wherein an electron mobility of the amorphous oxide increases when the electron carrier concentration increases.
51. An active matrix display device comprising pixel circuits arranged into a two-dimensional matrix form, each of the pixel circuits comprising:
a light-emitting element comprising first and second electrodes; and
a light-emitting layer existing between the first and second electrodes and a field effect transistor for driving the light-emitting element, wherein an active layer of the field effect transistor comprises an amorphous oxide of a compound having
(a) a composition selected from an oxide containing In, Ga, and Zn, an oxide containing In, Zn, and Sn, an oxide containing In and Sn, and an oxide containing In;
(b) an electron carrier concentration of greater than 10 12 /cm 3 and lesser than 10 18 /cm 3 , wherein the amorphous oxide semiconductor is capable of realizing a normally off state such that a current between a drain terminal and a source terminal of the field effect transistor when no gate voltage is applied is less than 10 microamperes; and
(c) an oxygen defect density decreased by treatment in an atmosphere including oxygen at a predetermined pressure during or after formation of the active layer of the amorphous oxide.
52. The active matrix display device according to claim 51 , wherein the amorphous oxide is an oxide which exhibits a halo pattern and no characteristic diffraction line in an x-ray diffraction spectrogram.
53. The active matrix display device according to claim 51 , wherein the amorphous oxide has an electron carrier concentration of less than 10 16 /cm 3 .
54. The light-emitting device according to claim 51 , wherein an electron mobility of the amorphous oxide increases when the electron carrier concentration increases.