Imaging element, stacked-type imaging element, imaging apparatus, and manufacturing method of imaging element

1. An imaging element which is formed by sequentially stacking at least an anode, an anode-side buffer layer, a photoelectric conversion layer, and a cathode,

wherein the photoelectric conversion layer comprises a thienoacene-based p-type material,

wherein the anode-side buffer layer comprises a material having structural formula (1):

in which thiophene and carbazole are combined,

where X 1 , X 2 , X 3 , and X 4 are each independently an arylamino group and may or may not have a substituent.

2. The imaging element according to claim 1 , wherein a difference between a HOMO value of the material forming the anode-side buffer layer and a HOMO value of the thienoacene-based p-type material is in a range of ±0.2 eV.

3. The imaging element according to claim 2 , wherein the HOMO value of the p-type material forming the photoelectric conversion layer is a value from −5.6 eV to −5.7 eV.

4. The imaging element according to claim 1 , wherein a carrier mobility of the material forming the anode-side buffer layer is higher than or equal to 5×10 −6 cm 2 /V·s.

5. The imaging element according to claim 1 , wherein an absorption spectrum of the material forming the anode-side buffer layer has an absorption maximum at a wavelength of 425 nm or lower.

6. The imaging element according to claim 1 , wherein the anode and the cathode are formed of a transparent conductive material.

7. The imaging element according to claim 1 , wherein one of the anode and the cathode is formed of a transparent conductive material and the other is formed of a metal material.

8. A stacked-type imaging element which is formed by stacking at least one of the imaging elements according to claim 1 .

9. An imaging apparatus comprising:

a plurality of imaging elements according to claim 1 .

10. An imaging apparatus comprising:

a plurality of stacked-type imaging elements according to claim 8 .

11. The imaging element according to claim 1 ,

wherein the photoelectric conversion layer further comprises a second p-type material and/or a n-type material, wherein the second p-type is selected from the group consisting of a naphthalene derivative, an anthracene derivative, a phenanthrene derivative, a pyrene derivative, a perylene derivative, a tetracene derivative, a pentacene derivative, a quinacridone derivative, a triallylamine derivative, a carbazole derivative, a picen derivative, a chrysen derivative, a fluoranthene derivative, a phthalocyanine derivative, a subphthalocyanine derivative, a subporphyrazine derivative, a metal complex having a heterocyclic compound as a ligand, a polythiophene derivative, a polybenzothiadiazole derivative, a polyfluorene derivative is included, and combinations thereof, and

wherein the n-type material is selected from the group consisting of fullerene, a fullerene derivative, a heterocyclic compound containing a nitrogen atom, an oxygen atom, and a sulfur atom, a pyridine derivative, a pyrazine derivative, a pyrimidine derivative, a triazine derivative, a quinoline derivative, a quinoxaline derivative, an isoquinoline derivative, an acridine derivative, a phenazine derivative, a benanthroline derivative, a tetrazole derivative, a pyrazole derivative, an imidazole derivative, a thiazole derivative, an oxazole derivative, an imidazole derivative, a benzimidazole derivative, a penzotriazole derivative, a benzoxazole derivative, a benzoxazole derivative, a carbazole derivative, a benzofuran derivative, a dibenzofuran derivative, a subporphyrazine derivative, a polyphenylene vinylene derivative, a polybenzothiadiazole derivative, a polyfluorene derivative, a subphthalocyanine derivative, and combinations thereof.

12. The imaging element according to claim 1 , wherein the photoelectric conversion layer includes an inorganic material selected from the group consisting of crystal silicon, amorphous silicon, microcrystalline silicon, crystalline selenium, amorphous selenium, CIGS (CuInGaSe), CIS (CuInSe 2 ), CuInS 2 , CuAlS 2 , CuAlSe 2 , CuGaS 2 , CuGaSe 2 , AgAlS 2 , AgAlSe 2 , AgInS 2 , AgInSe 2 , GaAs, InP, AlGaAs, InGaP, AlGaInP, InGaAsP, CdSe, CdS, In 2 Se 3 , In 2 S 3 , Bi 2 Se 3 , Bi 2 S 3 , ZnSe, ZnS, PbSe, PbS, a quantum dot formed thereof, and combinations thereof.

13. The imaging element according to claim 1 , wherein the thienoacene-based p-type material comprises one or more of a thiophene derivative, a thienothiophene derivative, a benzothiophene derivative, a benzothienobenzothiophene (BTBT) derivative, a dinaphthothienothiophene (DNTT) derivative, a diantrasenothienothiophene (DATT) derivative, a benzobisbenzothiophene (BBBT) derivative, a thienobis benzothiophene (TBBT) derivative, a dibenzothienobisbenzothiophene (DBTBT) derivative, a dithienobenzodithiophene (DTBDT) derivative, a dibenzothienodithiophene (DBTDT) derivative, a benzodithiophene (BDT) derivative, a naphthodithiophene (NDT) derivative, an anthracenodithiophene (ADT) derivative, a tetrasenodithiophene (TDT) derivative, and a pentasenodithiophene (PDT) derivative.

14. The imaging element according to claim 1 , wherein the imaging element further comprises a cathode-side buffer layer interposed between the photoelectric conversion layer and the cathode, wherein a work function of a material of the cathode side buffer layer is greater than a work function of the material of the anode side buffer layer.

15. The imaging element according to claim 1 , wherein each of X 1 , X 2 , X 3 , and X 4 of the material having structural formula (1) is a 3,6-bis(diphenylaminyl)carbazole group.

16. An imaging element which is formed by sequentially stacking at least an anode, an anode-side buffer layer, a photoelectric conversion layer, and a cathode,

wherein the photoelectric conversion layer comprises a thienoacene-based p-type material,

wherein the anode-side buffer layer comprises a material having structural formula (2):

in which thiophene and carbazole are combined,

where Y 1 , Y 2 , Y 3 , Y 4 , Y 5 , Y 6 , Y 7 , and Y 8 are each independently a group consisting of an alkyl group, an aryl group, an arylamino group, an aryl group having an arylamino group as a substituent, and a carbazolyl group, and may or may not have a substituent,

the aryl group and the aryl group having an arylamino group as a substituent are an aryl group selected from a group consisting of a phenyl group, a biphenyl group, a naphthyl group, a naphthyl phenyl group, a phenyl naphthyl group, a tolyl group, a xylyl group, a terphenyl group, an anthracenyl group, a phenanthryl group, a pyrenyl group, a tetracenyl group, a fluoranthenyl group, a pyridinyl group, a quinolinyl group, an acridinyl group, an indole group, an imidazole group, a benzimidazole group, and a thienyl group, and

the alkyl group may be an alkyl group selected from the group consisting of a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group, or a linear or branched alkyl group.

17. An imaging element which is formed by sequentially stacking at least an anode, an anode-side buffer layer, a photoelectric conversion layer, and a cathode,

wherein the photoelectric conversion layer comprises a thienoacene-based p-type material,

wherein the anode-side buffer layer comprises a material having structural formula (3):

where Ar 1 , Ar 2 , Ar 3 , Ar 4 , Ar 5 , Ar 6 , Ar 7 , and Ar 8 are each independently an aryl group selected from the group consisting of a phenyl group, a biphenyl group, a naphthyl group, a naphthyl phenyl group, a phenyl naphthyl group, a tolyl group, a xylyl group, a terphenyl group, an anthracenyl group, a phenanthryl group, a pyrenyl group, a tetracenyl group, a fluoranthenyl group, a pyridinyl group, a quinolinyl group, an acridinyl group, an indole group, an imidazole group, a benzimidazole group, and a thienyl group.

18. The imaging element according to claim 17 , wherein the anode-side buffer layer includes a material having structural formula (4) or structural formula (5):

in which thiophene and carbazole are combined.

19. A manufacturing method of an imaging element which is formed by sequentially stacking at least an anode, an anode-side buffer layer, a photoelectric conversion layer, and a cathode,

wherein the photoelectric conversion layer comprises a thienoacene-based p-type material,

wherein the anode-side buffer layer comprises a material having structural formula (1):

in which thiophene and carbazole are combined, and

the anode-side buffer layer is formed by using a physical vapor deposition method,

where X 1 , X 2 , X 3 , and X 4 are each independently an arylamino group and may or may not have a substituent.