Imaging device
A multifunctional imaging device is provided. The imaging device includes first to fourth light-receiving elements and first and second functional layers. The first to fourth light-receiving elements are photoelectric conversion elements having sensitivity to light of different wavelengths from each other. The first and second functional layers each include first and second transistors. The first functional layer and the fourth to first light-receiving elements are stacked in this order over the second functional layer. In each of the first to fourth light-receiving elements, a first conductive layer, a first buffer layer, a photoelectric conversion layer, a second buffer layer, and a second conductive layer are stacked in this order. The photoelectric conversion layer includes an organic compound, and the first buffer layer and the second buffer layer each include a metal or an organic compound. The first transistor is electrically connected to the first conductive layer of any of the first to fourth light-receiving elements. The second transistor is electrically connected to the first transistor.
1. An imaging device comprising a first light-receiving element, a second light-receiving element, a third light-receiving element, a fourth light-receiving element, a first functional layer, and a second functional layer,
wherein the first light-receiving element is a photoelectric conversion element having sensitivity to light of a first wavelength,
wherein the second light-receiving element is a photoelectric conversion element having sensitivity to light of a second wavelength,
wherein the third light-receiving element is a photoelectric conversion element having sensitivity to light of a third wavelength,
wherein the fourth light-receiving element is a photoelectric conversion element having sensitivity to light of a fourth wavelength,
wherein the first functional layer comprises a first transistor,
wherein the second functional layer comprises a second transistor,
wherein the first functional layer, the fourth light-receiving element, the third light-receiving element, the second light-receiving element, and the first light-receiving element are stacked in this order over the second functional layer,
wherein each of the first light-receiving element, the second light-receiving element, the third light-receiving element, and the fourth light-receiving element has a stacked-layer structure in which a first conductive layer, a first buffer layer, a photoelectric conversion layer, a second buffer layer, and a second conductive layer are stacked in this order,
wherein the photoelectric conversion layer comprises an organic compound,
wherein each of the first buffer layer and the second buffer layer comprises a metal or an organic compound,
wherein the first transistor is electrically connected to the first conductive layer included in any one of the first light-receiving element, the second light-receiving element, the third light-receiving element, and the fourth light-receiving element, and
wherein the second transistor is electrically connected to the first transistor.
2. An imaging device comprising a first light-receiving element, a second light-receiving element, a third light-receiving element, a fourth light-receiving element, a first functional layer, and a second functional layer,
wherein the first light-receiving element is a photoelectric conversion element having sensitivity to light of a first wavelength,
wherein the second light-receiving element is a photoelectric conversion element having sensitivity to light of a second wavelength,
wherein the third light-receiving element is a photoelectric conversion element having sensitivity to light of a third wavelength,
wherein the fourth light-receiving element is a photoelectric conversion element having sensitivity to light of a fourth wavelength,
wherein the first functional layer comprises a first transistor,
wherein the second functional layer comprises a second transistor,
wherein the first functional layer, the fourth light-receiving element, the third light-receiving element, the second light-receiving element, and the first light-receiving element are stacked in this order over the second functional layer,
wherein each of the first light-receiving element, the second light-receiving element, and the third light-receiving element has a stacked-layer structure in which a first conductive layer, a first buffer layer, a photoelectric conversion layer, a second buffer layer, and a second conductive layer are stacked in this order,
wherein the photoelectric conversion layer comprises an organic compound,
wherein each of the first buffer layer and the second buffer layer comprises a metal or an organic compound,
wherein the fourth light-receiving element is provided on a first single crystal substrate and comprises a photoelectric conversion portion having a pn junction in the first single crystal substrate,
wherein the first transistor is electrically connected to the first conductive layer included in any one of the first light-receiving element, the second light-receiving element, and the third light-receiving element, and
wherein the second transistor is electrically connected to the first transistor.
3. The imaging device according to claim 2 , wherein the first transistor is provided on the first single crystal substrate and comprises a channel formation region in the first single crystal substrate.
4. The imaging device according to claim 1 , wherein the first transistor comprises silicon in a channel formation region.
5. The imaging device according to claim 1 , wherein the first transistor comprises an oxide semiconductor in a channel formation region.
6. The imaging device according to claim 2 , wherein the second transistor is provided on the first single crystal substrate and comprises a channel formation region in the first single crystal substrate.
7. The imaging device according to claim 6 , further comprising a third functional layer between the first functional layer and the second functional layer,
wherein the third functional layer comprises a third transistor, and
wherein the third transistor comprises an oxide semiconductor in a channel formation region.
8. The imaging device according to claim 1 , further comprising a plug,
wherein the plug electrically connects one of a source and a drain of the first transistor and the first conductive layer included in the first light-receiving element to each other,
wherein the photoelectric conversion layer included in the second light-receiving element comprises a first opening portion,
wherein the second conductive layer included in the second light-receiving element comprises a second opening portion,
wherein the plug comprises a portion that is in contact with the photoelectric conversion layer in the first opening portion, and
wherein the plug comprises a portion positioned inside the second opening portion and is in contact with neither the first conductive layer nor the second conductive layer included in the second light-receiving element.
9. The imaging device according to claim 1 , further comprising a plug,
wherein the plug electrically connects one of a source and a drain of the first transistor and the first conductive layer included in the first light-receiving element to each other,
wherein the photoelectric conversion layer included in the second light-receiving element comprises a first opening portion,
wherein the second conductive layer included in the second light-receiving element comprises a second opening portion, and
wherein the plug comprises a portion positioned inside the first opening portion and a portion positioned inside the second opening portion and is in contact with neither the first conductive layer, the photoelectric conversion layer, nor the second conductive layer included in the second light-receiving element.
10. The imaging device according to claim 1 , wherein any three of the light of the first wavelength, the light of the second wavelength, the light of the third wavelength, and the light of the fourth wavelength are visible light and the other is infrared light or ultraviolet light.
11. The imaging device according to claim 1 , wherein wavelengths are shorter in the order of the first wavelength, the second wavelength, the third wavelength, and the fourth wavelength.
12. The imaging device according to claim 1 , wherein the second transistor is provided on a first single crystal substrate and comprises a channel formation region in the first single crystal substrate.