The invention claimed is:
1. A photoelectric conversion element comprising:a first electrode;a second electrode that is opposed to the first electrode; andan organic photoelectric conversion layer that is provided between the first electrode and the second electrode, and includes, as a first organic semiconductor material, a benzothienobenzothiophene-based compound represented by the following general formula (1):
(R1 to R4 are each independently a phenyl group, a biphenyl group, a terphenyl group, a naphthalene group, a phenylnaphthalene group, a biphenylnaphthalene group, a binaphthalene group, a thiophene group, a bithiophene group, a terthiophene group, a benzothiophene group, a phenyl benzothiophene group, a biphenyl benzothiophene benzofuran group, a phenyl benzofuran group, a biphenyl benzothiophene group, an alkane group, a cycloalkane group, a fluorene group, a phenylfluorene group, or any of derivatives thereof).2. The photoelectric conversion element according to claim 1, wherein the organic photoelectric conversion layer further includes fullerene or a fullerene derivative as a second organic semiconductor material.3. The photoelectric conversion element according to claim 1, wherein the organic photoelectric conversion layer further includes a third organic semiconductor material.4. The photoelectric conversion element according to claim 3, wherein the third organic semiconductor material absorbs light of any of wavelengths from 400 nm to 700 nm both inclusive.5. The photoelectric conversion element according to claim 1, wherein the organic photoelectric conversion layer absorbs light of all wavelengths within a range from 400 nm to 700 nm both inclusive.6. The photoelectric conversion element according to claim 1, wherein the first electrode includes a plurality of electrodes.7. The photoelectric conversion element according to claim 1, wherein a first electric charge blocking layer is further provided between the first electrode and the organic photoelectric conversion layer.8. The photoelectric conversion element according to claim 1, wherein a second electric charge blocking layer is further provided between the organic photoelectric conversion layer and the second electrode.9. An imaging device provided with a plurality of pixels each including one or a plurality of organic photoelectric converters, the organic photoelectric converters each comprising:a first electrode;a second electrode that is opposed to the first electrode; andan organic photoelectric conversion layer that is provided between the first electrode and the second electrode, and includes, as a first organic semiconductor material, a benzothienobenzothiophene-based compound represented by the following general formula (1);
(R1 to R4 are each independently a phenyl group, a biphenyl group, a terphenyl group, a naphthalene group, a phenylnaphthalene group, a biphenylnaphthalene group, a binaphthalene group, a thiophene group, a bithiophene group, a terthiophene group, a benzothiophene group, a phenyl benzothiophene group, a biphenyl benzothiophene benzofuran group, a phenyl benzofuran group, a biphenyl benzothiophene group, an alkane group, a cycloalkane group, a fluorene group, a phenylfluorene group, or any of derivatives thereof).10. The imaging device according to claim 9, wherein one or a plurality of the organic photoelectric converters and one or a plurality of inorganic photoelectric converters that performs photoelectric conversion in a wavelength band different from the organic photoelectric converters are stacked in each of the pixels.11. The imaging device according to claim 10, whereinthe inorganic photoelectric converter is formed to be embedded in a semiconductor substrate, andthe organic photoelectric converter is formed on a first surface side of the semiconductor substrate.12. The imaging device according to claim 11, wherein the semiconductor substrate has a second surface that is opposed to the first surface, and a multilayer wiring layer is formed on the second surface side.13. The imaging device according to claim 11, whereinthe organic photoelectric converter performs photoelectric conversion of blue light, andan inorganic photoelectric converter that performs photoelectric conversion of green light and an inorganic photoelectric converter that performs photoelectric conversion of red light are stacked in the semiconductor substrate.14. The imaging device according to claim 9, wherein a plurality of the organic photoelectric converters that performs photoelectric conversion in wavelength bands different from each other is stacked in each of the pixels.