Photodetector element, manufacturing method for photodetector element, and image sensor
A photodetector element includes a photoelectric conversion layer that contains aggregates of semiconductor quantum dots between a first electrode layer and a second electrode layer, where the first electrode layer is provided on a light incident side with respect to the second electrode layer, and a wavelength λ (nm) of target light to be detected by the photodetector element and an optical path length L λ (nm) of light having the wavelength λ, from a surface of the second electrode layer on a side of the photoelectric conversion layer to a surface of the photoelectric conversion layer on a side of the first electrode layer satisfy a relationship of the following Expression (1). m is an integer of 0 or more. 0.05+ m /2≤ L λ /λ≤0.35+ m /2 (1)
1. A photodetector element comprising:
a photoelectric conversion layer that contains aggregates of semiconductor quantum dots between a first electrode layer and a second electrode layer,
wherein the first electrode layer is provided on a light incident side with respect to the second electrode layer,
wherein the photoelectric conversion layer contains a ligand that is coordinated to the semiconductor quantum dot,
wherein the ligand contains a ligand containing a halogen atom and a polydentate ligand containing two or more coordination moieties, and the ligand containing a halogen atom is a salt of a metal atom and the halogen atom, and
a wavelength λ (nm) of target light to be detected by the photodetector element and an optical path length L λ (nm) of light having the wavelength λ from a surface of the second electrode layer on a side of the photoelectric conversion layer to a surface of the photoelectric conversion layer on a side of the first electrode layer satisfy a relationship of the following Expression (1);
0.05+ m/ 2≤ L λ /λ≤0.35+ m/ 2 (1)
in the expression, λ is the wavelength of the target light to be detected by the photodetector element,
L λ is the optical path length of the light having the wavelength λ from a surface of the second electrode layer on a side of the photoelectric conversion layer to a surface of the photoelectric conversion layer on a side of the first electrode layer, and
m is an integer of 0 or more.
2. The photodetector element according to claim 1 ,
wherein the wavelength λ of the target light to be detected by the photodetector element and the optical path length L λ of the light having the wavelength λ from a surface of the second electrode layer on a side of the photoelectric conversion layer to a surface of the photoelectric conversion layer on a side of the first electrode layer satisfy a relationship of the following Expression (2);
0.10+ m/ 2≤ L λ /2≤0.30+ m/ 2 (2)
in the expression, λ is the wavelength of the target light to be detected by the photodetector element,
L λ is the optical path length of the light having the wavelength λ from a surface of the second electrode layer on a side of the photoelectric conversion layer to a surface of the photoelectric conversion layer on a side of the first electrode layer, and
m is an integer of 0 or more.
3. The photodetector element according to claim 1 ,
wherein m is an integer of 0 to 4.
4. The photodetector element according to claim 1 ,
wherein m is an integer of 0 to 2.
5. The photodetector element according to claim 1 ,
wherein the photoelectric conversion layer has a film thickness of 150 to 600 nm.
6. The photodetector element according to claim 1 ,
wherein the semiconductor quantum dot contains a Pb atom.
7. The photodetector element according to claim 1 ,
wherein the semiconductor quantum dot contains PbS.
8. The photodetector element according to claim 1 ,
wherein a refractive index of the photoelectric conversion layer with respect to the light having the wavelength 2 is 2 to 3.
9. The photodetector element according to claim 1 , further comprising a charge transport layer between the photoelectric conversion layer and the second electrode layer.
10. The photodetector element according to claim 1 ,
wherein the target light to be detected by the photodetector element is light having a wavelength range of 900 to 1,600 nm.
11. A manufacturing method for the photodetector element according claim 1 , the manufacturing method comprising:
a step of using a semiconductor quantum dot dispersion liquid that contains the semiconductor quantum dots, the ligand that is coordinated to the semiconductor quantum dot, and a solvent, to form a film of aggregates of the semiconductor quantum dots.
12. An image sensor comprising the photodetector element according to claim 1 .