Semiconductor film, photoelectric conversion element, solid-state imaging element, and electronic device

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Solution Overview

Problem

Existing semiconductor films for photoelectric conversion elements and light emitting devices face challenges in achieving high photoelectric conversion efficiency and light emission efficiency due to surface defects and poor ligand coordination, leading to recombination of electrons and holes and low carrier mobility.

Innovation Solution

A semiconductor film comprising semiconductor nanoparticles coordinated with a compound represented by specific general formulas, which enhances carrier mobility by shortening inter-particle distances and improving surface coverage, thereby reducing dark current and increasing photoelectric conversion efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional ligands are used to coordinate semiconductor quantum dots, then the semiconductor film can be formed, but surface defects remain and photoelectric conversion efficiency is insufficient

Engineering Contradiction:
Improvephotoelectric conversion efficiencyVSAvoidsurface defects
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical parameters of the ligand by selecting compounds with specific functional groups (carboxylic acid, phosphonic acid, sulfonic acid, or amine groups) that can strongly coordinate to metal atoms on semiconductor quantum dot surfaces. This parameter change in ligand chemistry enables effective passivation of surface defects while maintaining film formability, thereby improving photoelectric conversion efficiency

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite structure where semiconductor quantum dots are coordinated with specific ligand molecules. This composite material approach combines the photoelectric properties of quantum dots with the defect-passivating capability of functional group-containing ligands, resulting in a semiconductor film with reduced surface defects and enhanced photoelectric conversion efficiency

Inventive Principle:
Principle #40Composite materials

2Reliability

If ligand exchange is performed to improve surface coverage, then surface defects are reduced, but inter-particle distance may increase and carrier mobility may decrease

Engineering Contradiction:
Improvesurface coverageVSAvoidcarrier mobility
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The patent optimizes the molecular structure parameters of the ligand by selecting compounds with appropriate chain lengths and functional group positions. This parameter optimization enables the ligand to provide both sufficient surface coverage for defect passivation and adequate spacing control to maintain high carrier mobility in the semiconductor film

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The proposed semiconductor film significantly enhances photoelectric conversion efficiency and light emission efficiency by reducing surface defects and improving carrier mobility, leading to improved image quality and reliability in digital cameras and other electronic devices.

Implementation Method 1

The semiconductor nanoparticles included in the semiconductor film according to the present technology may selectively absorb at least light in a visible region. The semiconductor nanoparticles included in the semiconductor film according to the present technology may selectively absorb at least light in an infrared region.

Methodology Applied
Scientific EffectPhotoelectric conversion: Photovoltaic Effect

Implementation Method 2

a semiconductor film including semiconductor nanoparticles and a compound represented by the following general formula (1), in which the compound represented by the general formula (1) is coordinated to the semiconductor nanoparticles

Methodology Applied
Scientific EffectLigand coordination: Chemical Bonding

Data Source

PatentEP3490002B1Semiconductor film, photoelectric conversion element, solid-state imaging element, and electronic device
Publication Date: 2024.05.01 SONY GROUP CORP
  • EP3490002B1 patent drawingFigure 1(a)~1(f)
  • EP3490002B1 patent drawingFigure 2
  • EP3490002B1 patent drawingFigure 3~4

AI summary

To provide a semiconductor film capable of realizing further enhancement of photoelectric conversion efficiency. The semiconductor film includes semiconductor nanoparticles and a compound represented by the following general formula (1), in which the compound represented by the general formula (1) is coordinated to the semiconductor nanoparticles. (In the general formula (1), X represents -SH, -COOH, -NH2, -PO(OH)2, or -SO2(OH), A1 represents -S, -COO, -PO(OH)O, or -SO2(O), and n is an integer of 1 to 3. B1 represents Li, Na, or K.)