Photoelectric Conversion Layer Using Composite Materials for Wavelength Selectivity

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Solution Overview

Problem

Existing imaging devices face challenges in achieving both high wavelength selectivity and high response speed, as improving one often compromises the other, leading to suboptimal sensitivity and color accuracy in photoelectric conversion elements.

Innovation Solution

A photoelectric conversion element is designed with a multilayer structure incorporating a high-molecular semiconductor material with an absorption coefficient of 50000 cm−1 or less in the visible light region and a low-molecular material with an absorption peak corresponding to a specific color range, forming a continuous carrier path to enhance sensitivity and response speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the wavelength selectivity is improved in the photoelectric conversion element, then the color accuracy is enhanced, but the response speed deteriorates

Engineering Contradiction:

Improvewavelength selectivityVSAvoidresponse speed

Core Design Contradiction:

Measurement precisionVSSpeed

Solution Approach 1:

The photoelectric conversion element uses a composite material consisting of high-molecular semiconductor material and low-molecular material. The high-molecular material provides broad light absorption with moderate absorption coefficient (50000 cm⁻¹ or less), while the low-molecular material contributes specific absorption peaks for wavelength selectivity. This composite structure enables both high wavelength selectivity and fast response speed by combining the advantages of different material types.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The invention controls the absorption coefficient parameter of the high-molecular semiconductor material to be 50000 cm⁻¹ or less in the visible light region. This parameter optimization allows sufficient light penetration and interaction with the low-molecular material, achieving wavelength selectivity while maintaining fast response characteristics through controlled optical interaction depth.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the absorption coefficient of the semiconductor material is increased to improve sensitivity, then the light absorption is enhanced, but the response speed and wavelength selectivity deteriorate

Engineering Contradiction:

ImprovesensitivityVSAvoidresponse speed

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The invention employs a composite material system where high-molecular semiconductor material with controlled absorption coefficient (≤50000 cm⁻¹) works synergistically with low-molecular material. This combination achieves high sensitivity through effective light absorption while maintaining fast response speed and wavelength selectivity, avoiding the trade-off present in single-material systems.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The photoelectric conversion element achieves different functional properties in different material components: the high-molecular material provides broad absorption and structural stability, while the low-molecular material provides wavelength-specific absorption peaks. This local differentiation of material properties enables simultaneous achievement of sensitivity, response speed, and wavelength selectivity.

Inventive Principle:

Principle #3Local quality

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

This configuration improves sensitivity to specific wavelengths and enables faster response times while maintaining high wavelength selectivity, addressing the limitations of previous technologies.

Implementation Method 1

a photoelectric conversion layer that is provided between the first electrode and the second electrode, and includes a high-molecular semiconductor material and a low-molecular material

Methodology Applied

Scientific EffectPhotoelectric conversion: Photoelectric Effect

Implementation Method 2

The low-molecular material includes an absorption peak in a wavelength range corresponding to one color in the visible light region

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentUS10879314B2Photoelectric conversion element, imaging device, and electronic apparatus

Publication Date: 2020.12.29 SONY SEMICON SOLUTIONS CORP

AI summary

A photoelectric conversion element according to one embodiment of the disclosure includes: a first electrode and a second electrode that are oppositely disposed; and a photoelectric conversion layer that is provided between the first electrode and the second electrode, and includes a high-molecular semiconductor material and a low-molecular material. The high-molecular semiconductor material has an absorption coefficient in a visible light region of 50000 cm−1 or less. The low-molecular material includes an absorption peak in a wavelength range corresponding to one color in the visible light region.