Semiconductor device having quantum dots, display device, imaging system, and moving body

Patent metadata

Field	Value
Publication number	US-2021242416-A1
Application number	US-202117161493-A
Country	US
Kind code	A1
Filing date	Jan 28, 2021
Priority date	Jan 31, 2020
Publication date	Aug 5, 2021
Grant date	—

Abstract

A semiconductor device includes an anode, a cathode, a first functional layer between the anode and cathode, and a second functional layer between the first functional layer and the cathode. The first functional layer contains a first quantum dot having a first ligand, and the second functional layer contains a second quantum dot having a second ligand different from the first ligand. The second ligand is an aromatic compound having a sulfide bond and an ester bond.

First claim

What is claimed is:

1 . A semiconductor device comprising:
an anode; a cathode; a first functional layer between the anode and the cathode, the first functional layer containing a first quantum dot having a first ligand; and a second functional layer between the first functional layer and the cathode, the second functional layer containing a second quantum dot having a second ligand different from the first ligand, the second ligand being an aromatic compound having a sulfide bond and an ester bond.

2 . A semiconductor device comprising:
an anode; a cathode; a first functional layer between the anode and the cathode, the first functional layer containing a first quantum dot having a first ligand; and a second functional layer between the first functional layer and the cathode, the second functional layer containing a second quantum dot having a second ligand different from the first ligand, wherein the conduction band minimum energy of the second quantum dot and the triplet excitation energy of the second ligand have a difference smaller than the difference between the conduction band minimum energy of the first quantum dot and the triplet excitation energy of the first ligand.

3 . The semiconductor device according to claim 2 , wherein the conduction band minimum energy of the second quantum dot is higher than the triplet excitation energy of the second ligand.

4 . The semiconductor device according to claim 2 , wherein the conduction band minimum energy of the second quantum dot and the triplet excitation energy of the second ligand have a difference of 0.8 eV or less.

5 . The semiconductor device according to claim 2 , wherein the conduction band minimum energy of the second quantum dot and the triplet excitation energy of the second ligand have a difference of 0.3 eV or less.

6 . A semiconductor device comprising:
an anode; a cathode; a first functional layer between the anode and the cathode, the first functional layer containing a first quantum dot having a first ligand; and a second functional layer between the first functional layer and the cathode, the second functional layer containing a second quantum dot having a second ligand different from the first ligand, wherein the conduction band minimum energy of the second quantum dot and the singlet excitation energy of the second ligand have a difference smaller than the difference between the conduction band minimum energy of the first quantum dot and the singlet excitation energy of the first ligand.

7 . The semiconductor device according to claim 6 , wherein the conduction band minimum energy of the second quantum dot is higher than the singlet excitation energy of the second ligand.

8 . The semiconductor device according to claim 6 , wherein the conduction band minimum energy of the second quantum dot and the singlet excitation energy of the second ligand have a difference of 0.3 eV or less.

9 . The semiconductor device according to claim 1 , wherein the first functional layer has a higher photoelectric conversion efficiency than the second functional layer.

10 . The semiconductor device according to claim 1 , wherein the second functional layer has a thickness of 25% or less relative to the distance between the anode and the cathode.

11 . The semiconductor device according to claim 1 , wherein the second functional layer has a thickness of 1.5% to 25% relative to the distance between the anode and the cathode.

12 . The semiconductor device according to claim 1 , wherein the second ligand of the second quantum dot contained in the second functional layer is selected from a group consisting of 4-mercaptobenzoic acid, 3-mercaptobenzoic acid, and 2-mercaptobenzoic acid.

13 . The semiconductor device according to claim 1 , wherein the first functional layer and the second functional layer are each a quantum dot film defined by colloidal quantum dots.

14 . The semiconductor device according to claim 1 , wherein at least one of the first and second functional layers contains a halogen selected from the group consisting of iodine, chlorine, bromine, and fluorine.

15 . The semiconductor device according to claim 1 , wherein the first functional layer and the second functional layer act as photoelectric conversion layers.

16 . The semiconductor device according to claim 1 , wherein the first and second quantum dots of the first and second functional layers contain PbS or PbSe.

17 . A display device comprising:
the semiconductor device as set forth in claim 1 ; and an active element coupled to the semiconductor device, the active element being operable to control the emission brightness of the semiconductor device.

18 . An imaging system comprising:
the semiconductor device as set forth in claim 1 , and a processor operable to process signals outputted from the semiconductor device.

19 . A moving body comprising:
the semiconductor device as set forth in claim 1 ; a moving device; a processor operable to acquire information from signals outputted from the semiconductor device; and a controller operable to control the moving device according to the information.

Assignees

• Canon Kk

Inventors

• Sumida Takayuki
• Shimazu Akira
• Yajima Takahiro
• Yamaguchi Tomona

Classifications

• H04N23/80

  Camera processing pipelines; Components thereof · CPC title

• H10K30/10

  comprising heterojunctions between organic semiconductors and inorganic semiconductors · CPC title

• H10K30/35 Primary

  comprising inorganic nanostructures, e.g. CdSe nanoparticles · CPC title

• Y02E10/549

  Organic PV cells · CPC title

• H10K2101/10

  Triplet emission · CPC title