Imaging device comprising pixel circuit and light-emitting device
A thin imaging device including a light source is provided. The imaging device includes a light-emitting device which emits infrared light. Infrared light emitted by the light-emitting device and reflected by a subject is received by a photoelectric conversion device included in a pixel circuit. Since an EL element is used as the light-emitting device, a thin imaging device with a light source can be formed. A pixel circuit utilizing an oxide semiconductor transistor having a property of low off-state current is used, whereby image capturing by a global shutter method is possible and a distortion-free image can be obtained even when the subject is moving.
1 . An imaging device comprising:
a pixel circuit; and
a light-emitting device,
the pixel circuit comprising:
a photoelectric conversion device comprising a photoelectric conversion layer; and
a transistor comprising a gate electrode,
the light-emitting device comprising:
a first electrode;
a second electrode; and
a light-emitting layer,
wherein the light-emitting layer is provided between the first electrode and the second electrode,
wherein the photoelectric conversion device comprises a region which does not overlap with the first electrode, and
wherein the gate electrode is directly above the photoelectric conversion device and under the second electrode, the gate electrode overlapping with both the photoelectric conversion device and the second electrode.
2 . The imaging device according to claim 1 , wherein the photoelectric conversion device comprises a region overlapping with the second electrode and the light-emitting layer.
3 . The imaging device according to claim 1 , wherein the light-emitting device emits infrared light.
4 . The imaging device according to claim 1 , wherein the second electrode is formed of a light-transmitting conductive film having a property of transmitting infrared light.
5 . The imaging device according to claim 1 , wherein at least one transistor included in the imaging device includes a metal oxide in its channel formation region, and the metal oxide includes In, Zn, and M (Mis Al, Ti, Ga, Sn, Y, Zr, La, Ce, Nd, or Hf).
6 . An electronic device comprising the imaging device according to claim 1 , and a display device.
7 . An imaging device comprising:
a pixel circuit; and
a light-emitting device,
the light-emitting device comprising:
a first electrode;
a second electrode; and
a light-emitting layer,
wherein the light-emitting layer is provided between the first electrode and the second electrode,
the pixel circuit comprising:
a photoelectric conversion device comprising a photoelectric conversion layer; and
a first transistor over an insulating surface,
wherein one electrode of the photoelectric conversion device is electrically connected to one of a source and a drain of the first transistor,
wherein a gate electrode of the first transistor is positioned over and overlapping with the photoelectric conversion device in a first direction perpendicular to the insulating surface,
wherein the second electrode is positioned over and overlapping with the gate electrode of the first transistor in the first direction, and
wherein the photoelectric conversion device comprises a region which does not overlap with the first electrode in the first direction.
8 . The imaging device according to claim 7 , wherein the photoelectric conversion device comprises a region overlapping with the second electrode and the light-emitting layer in the first direction.
9 . The imaging device according to claim 7 , wherein the light-emitting device emits infrared light.
10 . The imaging device according to claim 7 , wherein the second electrode is formed of a light-transmitting conductive film having a property of transmitting infrared light.
11 . The imaging device according to claim 7 , wherein at least one transistor included in the imaging device includes a metal oxide in its channel formation region, and the metal oxide includes In, Zn, and M (Mis Al, Ti, Ga, Sn, Y, Zr, La, Ce, Nd, or Hf).
12 . An electronic device comprising the imaging device according to claim 7 , and a display device.
13 . An imaging device comprising:
a pixel circuit; and
a light-emitting device,
the light-emitting device comprising:
a first electrode;
a second electrode; and
a light-emitting layer,
wherein the light-emitting layer is provided between the first electrode and the second electrode,
wherein the light-emitting device emits light to an upper side,
the pixel circuit comprising:
a photoelectric conversion device comprising a photoelectric conversion layer; and
a first transistor over an insulating surface,
wherein one electrode of the photoelectric conversion device is electrically connected to one of a source and a drain of the first transistor,
wherein a gate electrode of the first transistor is positioned over and overlapping with the photoelectric conversion device in a first direction perpendicular to the insulating surface,
wherein the second electrode is positioned over and overlapping with the gate electrode of the first transistor in the first direction, and
wherein the photoelectric conversion device comprises a region which does not overlap with the first electrode in the first direction.
14 . The imaging device according to claim 13 , wherein the photoelectric conversion device comprises a region overlapping with the second electrode and the light-emitting layer in the first direction.
15 . The imaging device according to claim 13 , wherein the light-emitting device emits infrared light.
16 . The imaging device according to claim 13 , wherein the second electrode is formed of a light-transmitting conductive film having a property of transmitting infrared light.
17 . The imaging device according to claim 13 , wherein at least one transistor included in the imaging device includes a metal oxide in its channel formation region, and the metal oxide includes In, Zn, and M (Mis Al, Ti, Ga, Sn, Y, Zr, La, Ce, Nd, or Hf).
18 . An electronic device comprising the imaging device according to claim 13 , and a display device.