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

1. A light detecting element comprising:

a first electrode;

a second electrode;

a photoelectric conversion layer disposed between the first electrode and the second electrode; and

a buffer layer disposed between the first electrode and the photoelectric conversion layer,

wherein the photoelectric conversion layer comprises quinacridone derivatives or a thienoacene-based material, and

wherein the buffer layer includes a material having structural formula (4) or structural formula (5):

in which thiophene and carbazole are combined.

2. The light detecting element according to claim 1 , wherein a difference between a HOMO value of the material forming the buffer layer and a HOMO value of a p-type material forming the photoelectric conversion layer is in a range of ±0.2 eV.

3. The light detecting 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 light detecting element according to claim 1 , wherein carrier mobility of the material forming the buffer layer is higher than or equal to 5×10 −6 cm 2 /V·s.

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

6. The light detecting element according to claim 1 , wherein the first electrode and the second electrode are formed of a transparent conductive material.

7. The light detecting element according to claim 1 , wherein a first one of the first electrode and the second electrode is formed of a transparent conductive material and a second one of the first electrode and the second electrode is formed of a metal material.

8. A stacked-type light detecting element which is formed by stacking at least one light detecting element according to claim 1 .

9. A light detecting apparatus comprising:

a plurality of light detecting elements according to claim 8 .

10. A light detecting apparatus comprising:

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

11. The light detecting element according to claim 1 ,

wherein the photoelectric conversion layer includes two or three types of semiconductor materials,

as a p-type organic semiconductor material, at least any one of a naphthalene derivative, an anthracene derivative, a phenanthrene derivative, a pyrene derivative, a perylene derivative, a tetracene derivative, a pentacene derivative, 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 dibenzothienobi sbenzothiophene (DB TB T) 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, a pentasenodithiophene (PDT) 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, and a polyfluorene derivative is included, and

as an n-type organic semiconductor material, at least any one 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, and a subphthalocyanine derivative is included.

12. The light detecting element according to claim 1 , wherein the photoelectric conversion layer includes crystal silicon, amorphous silicon, microcrystalline silicon, crystalline selenium, amorphous selenium, and a compound semiconductor material including CIGS (CuInGaSe), CIS (CuInSe 2 ), CuInS 2 , CuAlS 2 , CuAlSe 2 , CuGaS 2 , CuGaSe 2 , AgAlS 2 , AgAlSe 2 , AgInS 2 , or AgInSe 2 , which is a chalcopyrite-based compound, GaAs, InP, AlGaAs, InGaP, AlGaInP, or InGaAsP, which is a Group III-V compound, and further CdSe, CdS, In2Se 3 , In 2 S 3 , Bi 2 Se 3 , Bi 2 S 3 , ZnSe, ZnS, Pb Se, or PbS, and/or a quantum dot formed of any of these materials.