Photoelectric conversion device, solid-state imaging device and manufacturing method of solid-state imaging device

Abstract

A photoelectric conversion device comprising a lower electrode, an upper electrode opposing to the lower electrode and a photoelectric conversion layer provided between the lower electrode and the upper electrode, the photoelectric conversion device being for collecting a photocurrent upon application of a bias voltage between the lower electrode and the upper electrode, wherein the upper electrode works as an electrode in a light incident side, the upper electrode is transparent, and the lower electrode is a metallic electrode having a function to reflect light.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view to show an outline configuration of a photoelectric conversion device for explaining a first embodiment of the invention.

FIG. 2 is a schematic cross-sectional view to show an outline configuration of a modification of a photoelectric conversion device for explaining a first embodiment of the invention.

FIG. 3 is a schematic cross-sectional view to show an outline configuration of a modification of a photoelectric conversion device for explaining a first embodiment of the invention.

FIG. 4 is a schematic cross-sectional view to show an outline configuration of a modification of a photoelectric conversion device for the purpose of explaining a first embodiment of the invention.

FIGS. 5A and 5B are each a graph to show results of Comparative Simulation.

FIGS. 6A and 6B are each a graph to show results of Simulation 1.

FIGS. 7A and 7B are each a graph to show results of Simulation 2.

FIGS. 8A and 8B are each a graph to show results of Simulation 3.

FIGS. 9A and 9B are each a graph to show results of Simulation 4.

FIGS. 10A and 10B are each a graph to show results of Simulation 5.

FIGS. 11A and 11B are each a graph to show results of Simulation 6.

FIG. 12 is a schematic cross-sectional view of one pixel of a solid-state imaging device using the photoelectric conversion device described in the first embodiment.

FIGS. 13A and 13B are each a view to show a disposition pattern of the pixel of the solid-state imaging device as illustrated in FIG. 12.

FIG. 14 is a graph to show results of Comparative Example 1.

FIG. 15 is a graph to show results of Example 1.

FIG. 16 is a graph to show results of Example 1.

FIG. 17 is a graph to show results of actually measuring an absorption factor of the device of Example 1.

FIG. 18 is a graph to show results of Example 2.

Claims

1. A photoelectric conversion device comprising a lower electrode, an upper electrode opposing to the lower electrode and a photoelectric conversion layer provided between the lower electrode and the upper electrode, the photoelectric conversion device being for collecting a photocurrent upon application of a bias voltage between the lower electrode and the upper electrode, wherein the upper electrode works as an electrode in a light incident side,the upper electrode is transparent, andthe lower electrode is a metallic electrode having a function to reflect light.

2. The photoelectric conversion device according to claim 1, further comprising a transparent electrode between the lower electrode and the photoelectric conversion layer.

3. The photoelectric conversion device according to claim 1, wherein the bias voltage is from 0.1 V to 30 V.

4. The photoelectric conversion device according to claim 1, wherein the photoelectric conversion layer contains an organic photoelectric conversion material.

5. The photoelectric conversion device according to claim 4, wherein the organic photoelectric conversion material comprises at least one of a material having a quinacridone skeleton, a material having a phthalocyanine skeleton and a material having an anthraquinone skeleton.

6. The photoelectric conversion device according to claim 1, wherein an absorption factor of a whole of the photoelectric conversion device against incident light is 80% or more in an absorption peak wavelength of the photoelectric conversion layer.

7. The photoelectric conversion device according to claim 1, wherein a half value width of an action spectrum of the photoelectric conversion device against incident light is not more than 130 nm.

8. The photoelectric conversion device according to claim 1, wherein the photoelectric conversion layer has a thickness of not more than 100 nm.

9. The photoelectric conversion device according to claim 1, further comprising a smoothing layer for reducing roughness of a surface of the photoelectric conversion layer provided between the photoelectric conversion layer and the upper electrode.

10. The photoelectric conversion device according to claim 9, wherein the smoothing layer comprises an amorphous material.

11. The photoelectric conversion device according to claim 9, wherein a mean surface roughness Ra of a surface of the smoothing layer is not more than 1 nm.

12. The photoelectric conversion device according to claim 9, wherein the smoothing layer comprises an organic material.

13. The photoelectric conversion device according to claim 9, wherein the smoothing layer is transparent.

14. The photoelectric conversion device according to claim 9, wherein the smoothing layer has a thickness of from 10 to 200 nm.

15. The photoelectric conversion device according to claim 1, wherein the upper electrode is a layer comprising a transparent conducting oxide.

16. The photoelectric conversion device according to claim 15, wherein the transparent conducting oxide is ITO.

17. The photoelectric conversion device according to claim 1, wherein the upper electrode is a metallic layer formed by vapor deposition.

18. The photoelectric conversion device according to claim 1, wherein the upper electrode has a thickness of from 5 to 200 nm.

19. The photoelectric conversion device according to claim 1, wherein a mean surface roughness Ra of a surface of the lower electrode is not more than 3 nm.

20. The photoelectric conversion device according to claim 1, wherein the lower electrode works as an electrode for collecting electrons, and the upper electrode works as an electrode for collecting holes.

21. The photoelectric conversion device according to claim 9, wherein the lower electrode works as an electrode for collecting electrons, the upper electrode works as an electrode for collecting holes, and the smoothing layer comprises a hole transporting material.

22. The photoelectric conversion device according to claim 21, wherein the hole transporting material is a material having a triphenylamine structure.

23. The photoelectric conversion device according to claim 22, wherein the hole transporting material is a material having a starburst amine structure.

24. The photoelectric conversion device according to claim 20, wherein a work function of the lower electrode is not more than 4.5 eV.

25. The photoelectric conversion device according to claim 24, wherein the lower electrode contains a metallic material selected from Ag, Al, Ca, In, Mg, Mn, Ta, Ti, V and W.

26. The photoelectric conversion device according to claim 1, wherein the lower electrode works as an electrode for collecting holes, and the upper electrode works as an electrode for collecting electrons.

27. The photoelectric conversion device according to claim 9, wherein the lower electrode works as an electrode for collecting holes, the upper electrode works as an electrode for collecting electrons, and the smoothing layer comprises an electron transporting material.

28. The photoelectric conversion device according to claim 27, wherein the electron transporting material is Alq3 or a derivative thereof.

29. The photoelectric conversion devices according to claim 26, wherein a work function of the lower electrode is 4.5 eV or more.

30. The photoelectric conversion device according to claim 29, wherein the lower electrode contains a metallic material selected from Au, Co, Fe, Mo, Pd and Pt.

31. The photoelectric conversion device according to claim 26, wherein a work function of the upper electrode is not more than 4.5 eV.

32. The photoelectric conversion device according to claim 31, wherein the upper electrode is made from Cs-doped ITO.

33. A solid-state imaging device comprising: a semiconductor substrate;a plurality of the photoelectric conversion devices according to claim 1 disposed in an array state on a same plane on the upper side of the semiconductor substrate; anda signal read-out part for reading out a signal corresponding to a signal charge generated in each of the plurality of photoelectric conversion devices.

34. The solid-state imaging device according to claim 33, wherein the signal read-out part is made from a CMOS circuit or CCD provided in the semiconductor substrate.

35. The solid-state imaging device according to claim 33, wherein a plurality of photoelectric conversion layers contained in the plurality of photoelectric conversion devices include plural kinds of photoelectric conversion layers each of which absorbs light of a different wavelength region to generate a charge corresponding thereto.

36. The solid-state imaging device according to claim 35, wherein the plurality of photoelectric conversion layers contained in the plurality of photoelectric conversion devices include three kinds of photoelectric conversion layers each of which absorbs light of a different wavelength region to generate a charge corresponding thereto, andthe three kinds of photoelectric conversion layers are disposed in a mosaic state.

37. The solid-state imaging device according to claim 35, wherein the plurality of photoelectric conversion layers contained in the plurality of photoelectric conversion devices include three kinds of photoelectric conversion layers each of which absorbs light of a different wavelength region to generate a charge corresponding thereto, andthe three kinds of photoelectric conversion layers are disposed in a stripe state.

38. A method for manufacturing the solid-state imaging device according to claim 35, which comprises: depositing materials for forming the photoelectric conversion layers on the same plane on the upper side of the semiconductor substrate with a mask so as to form the photoelectric conversion layers.