Photodetector element and image sensor

Patent metadata

Field	Value
Publication number	US-2022077238-A1
Application number	US-202117529268-A
Country	US
Kind code	A1
Filing date	Nov 18, 2021
Priority date	Jul 1, 2019
Publication date	Mar 10, 2022
Grant date	—

Abstract

A photodetector element has a photoelectric conversion layer containing aggregates of semiconductor quantum dots QD1 that contain a metal atom and containing a ligand L1 that is coordinated to the semiconductor quantum dot QD1, and a hole transport layer containing aggregates of semiconductor quantum dots QD2 that contains a metal atom and containing a ligand L2 that is coordinated to the semiconductor quantum dot QD2, the hole transport layer being arranged on the photoelectric conversion layer, where the ligand L2 includes a ligand represented by any one of Formulae (A) to (C).

First claim

What is claimed is:

1 . A photodetector element comprising:
a photoelectric conversion layer containing aggregates of semiconductor quantum dots QD1 that contain a metal atom and containing a ligand L1 that is coordinated to the semiconductor quantum dot QD1; and a hole transport layer containing aggregates of semiconductor quantum dots QD2 that contains a metal atom and containing a ligand L2 that is coordinated to the semiconductor quantum dot QD2, the hole transport layer being arranged on the photoelectric conversion layer, wherein the ligand L2 includes a ligand represented by any one of Formulae (A) to (C),

in Formula (A), X A1 and X A2 each independently represent a thiol group, an amino group, a hydroxy group, a carboxy group, a sulfo group, a phospho group, or a phosphonic acid group, and
L A1 represents a hydrocarbon group, where X A1 is a group different from X A2 ;
in Formula (B), X B1 and X B2 each independently represent a thiol group, an amino group, a hydroxy group, a carboxy group, a sulfo group, a phospho group, or a phosphonic acid group,
X B3 represents S, O, or NH, and
L B1 and L B2 each independently represent a hydrocarbon group;
in Formula (C), X C1 to X C3 each independently represent a thiol group, an amino group, a hydroxy group, a carboxy group, a sulfo group, a phospho group, or a phosphonic acid group,
X C4 represents N, and
L C1 to L C3 each independently represent a hydrocarbon group.

2 . The photodetector element according to claim 1 ,
wherein one of X A1 or X A2 in Formula (A) is a thiol group, at least one of X B1 or X B2 in Formula (B) is a thiol group, and at least one of X C1 to X C3 in Formula (C) is a thiol group.

3 . The photodetector element according to claim 1 ,
wherein the ligand L2 is at least one selected from thioglycolic acid, 3-mercaptopropionic acid, 2-aminoethanethiol, or 2-mercaptoethanol.

4 . The photodetector element according to claim 1 ,
wherein the ligand L1 includes a ligand different from the ligand L2.

5 . The photodetector element according to claim 1 ,
wherein the ligand L1 contains a ligand containing a halogen atom and a polydentate ligand containing two or more coordination moieties.

6 . The photodetector element according to claim 5 ,
wherein the ligand containing a halogen atom is an inorganic halide.

7 . The photodetector element according to claim 6 ,
wherein the inorganic halide contains a Zn atom.

8 . The photodetector element according to claim 5 ,
wherein the ligand containing a halogen atom contains an iodine atom.

9 . The photodetector element according to claim 1 ,
wherein the semiconductor quantum dot QD1 and the semiconductor quantum dot QD2 each contain a Pb atom.

10 . The photodetector element according to claim 1 ,
wherein the semiconductor quantum dot QD1 and the semiconductor quantum dot QD2 each contain the same kind of semiconductor quantum dot.

11 . The photodetector element according to claim 1 ,
wherein the semiconductor quantum dot QD1 and the semiconductor quantum dot QD2 each contain PbS.

12 . The photodetector element according to claim 1 ,
wherein an energy difference ΔE1 between a Fermi level of the photoelectric conversion layer and a conductor lower end and an energy difference ΔE2 between a Fermi level of the hole transport layer and the conductor lower end satisfy a relationship of Expression (1),
(Δ E 2 −ΔE 1)≥0.1 [eV]  (1).

13 . The photodetector element according to claim 1 ,
wherein the photodetector element is a photodiode-type photodetector element.

14 . An image sensor comprising the photodetector element according to claim 1 .

15 . The image sensor according to claim 14 ,
wherein the image sensor is an infrared image sensor.

Assignees

• Fujifilm Corp

Inventors

• Takata Masahiro
• Ono Masashi
• Kitajima Shunsuke

Classifications

• H04N25/70

  SSIS architectures; Circuits associated therewith · CPC title

• H04N23/20

  for generating image signals from infrared radiation only · CPC title

• H10K39/32

  Organic image sensors · CPC title

• C09K11/661 Primary

  Chalcogenides · CPC title

• H10F30/20

  the devices having potential barriers, e.g. phototransistors · CPC title