Photoelectric conversion device and solid-state imaging device
A photoelectric conversion device comprising a photoelectric conversion part including a first electrode, a second electrode opposing to the first electrode and a photoelectric conversion layer provided between the first electrode and the second electrode, wherein a smoothing layer for reducing roughness of a surface of the photoelectric conversion layer is provided between the first electrode or the second electrode and the photoelectric conversion layer.
1. A photoelectric conversion device comprising a photoelectric conversion part including a first electrode, a second electrode opposing to the first electrode and a photoelectric conversion layer provided between the first electrode and the second electrode, wherein
a smoothing layer for reducing roughness of a surface of the photoelectric conversion layer is provided as a single layer on the photoelectric conversion layer and in direct contact with the first electrode or the second electrode and the photoelectric conversion layer; wherein
the smoothing layer comprises an amorphous material;
the smoothing layer comprises an organic material;
the smoothing layer is transparent, and
the smoothing layer has a surface having a mean surface roughness Ra of not more than 1 nm.
2. The photoelectric conversion device according to claim 1 , wherein the photoelectric conversion layer comprises an organic polycrystalline material.
3. The photoelectric conversion device according to claim 2 , wherein the organic polycrystalline material contains a material having a quinacridone skeleton.
4. The photoelectric conversion device according to claim 1 , wherein the smoothing layer has a thickness of from 10 to 300 nm.
5. A photoelectric conversion device comprising a photoelectric conversion part including a first electrode, a second electrode opposing to the first electrode, a photoelectric conversion layer provided between the first electrode and the second electrode, and a smoothing layer for reducing roughness of a surface of the photoelectric conversion layer,
wherein the second electrode is an electrode in a light incident side;
the smoothing layer is provided as a single layer on the photoelectric conversion layer and is in direct contact with the second electrode and the photoelectric conversion layer; wherein
the smoothing layer comprises an amorphous material;
the smoothing layer comprises an organic material;
the smoothing layer is transparent;
the smoothing layer has a surface having a mean surface roughness Ra of not more than 1 nm, and
the first electrode is an electrode for collecting electrons, and the second electrode is an electrode for collecting holes.
6. The photoelectric conversion device according to claim 5 , wherein the smoothing layer comprises a hole transporting material.
7. The photoelectric conversion device according to claim 6 , wherein the hole transporting material has a triphenylamine structure.
8. The photoelectric conversion device according to claim 7 , wherein the hole transporting material has a starburst amine structure.
9. The photoelectric conversion device according to claim 5 , wherein the first electrode has a work function of not more than 4.5 eV.
10. The photoelectric conversion device according to claim 1 , wherein the first electrode is ITO, and a layer of In is provided between the ITO and the photoelectric conversion layer.
11. A photoelectric conversion device comprising a photoelectric conversion part including a first electrode, a second electrode opposing to the first electrode, a photoelectric conversion layer provided between the first electrode and the second electrode, and a smoothing layer for reducing roughness of a surface of the photoelectric conversion layer, wherein
the second electrode is an electrode in a light incident side;
the smoothing layer is provided as a single layer on the photoelectric conversion layer and is in direct contact with the second electrode and the photoelectric conversion layer; wherein
the smoothing layer comprises an amorphous material;
the smoothing layer comprises an organic material;
the smoothing layer is transparent;
the smoothing layer has a surface having a mean surface roughness Ra of not more than 1 nm, and
the first electrode is an electrode for collecting holes, and the second electrode is an electrode for collecting electrons.
12. The photoelectric conversion device according to claim 11 , wherein the smoothing layer comprises an electron transporting material.
13. The photoelectric conversion device according to claim 12 , wherein the electron transporting material is Alq3.
14. The photoelectric conversion device according to claim 11 , wherein the second electrode has a work function of not more than 4.4 eV.
15. The photoelectric conversion device according to claim 14 , wherein the second electrode is Cs-doped ITO.
16. The photoelectric conversion device according to claim 1 , wherein at least one of the first electrode and the second electrode is a transparent electrode.
17. The photoelectric conversion device according to claim 16 , wherein both the first electrode and the second electrode are a transparent electrode.
18. The photoelectric conversion device according to claim 16 , wherein the transparent electrode is a layer containing a transparent conductive oxide.
19. The photoelectric conversion device according to claim 18 , wherein the transparent conductive oxide is ITO.
20. The photoelectric conversion device according to claim 16 , wherein the transparent electrode is a layer made of a metal formed by vapor deposition.
21. The photoelectric conversion device according to claim 1 , wherein the first electrode and the second electrode each has a thickness of from 5 to 200 nm.
22. The photoelectric conversion device according to claim 1 , which comprises:
a semiconductor substrate having at least one of the photoelectric conversion part stacked on the upper side thereof;
a charge storage part in the semiconductor substrate for storing a charge generated in the photoelectric conversion layer in the photoelectric conversion part; and
a connecting part for electrically connecting the first electrode or the second electrode of the photoelectric conversion part to the charge storage part.
23. The photoelectric conversion device according to claim 22 , further comprising a photoelectric conversion part in the semiconductor substrate for absorbing light which has transmitted through the photoelectric conversion layer in the photoelectric conversion part, generating a charge corresponding to the light and storing the generated charge in the semiconductor substrate.
24. The photoelectric conversion device according to claim 23 , wherein the photoelectric conversion part within the semiconductor substrate comprises plural photodiodes stacked within the semiconductor substrate for absorbing light of a different color, respectively.
25. The photoelectric conversion device according to claim 23 , wherein the photoelectric conversion part in the semiconductor substrate comprises plural photodiodes within the semiconductor substrate for absorbing light of a different color, respectively, arranged in a direction vertical to a direction of the incident light.
26. The photoelectric conversion device according to claim 24 , wherein
one of the photoelectric conversion part is stacked on the upper side of the semiconductor substrate,
the plural photodiodes are a photodiode having a p-n junction provided in a suitable position for absorbing blue light and a photodiode having a p-n junction provided in a suitable position for absorbing red light, and
the photoelectric conversion layer in the photoelectric conversion part absorbs green light.
27. A solid-state imaging device including a number of the photoelectric conversion device according to claim 22 , provided in an array state, wherein a signal read-out part for reading out a signal corresponding to the charge stored in each of the plural photoelectric conversion devices is provided.