Organic Light-Receiving Device with Dual-Compound Active Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current light-receiving devices with integrated light-emitting elements face challenges in efficiently detecting visible light due to limitations in the absorption spectra and carrier transport properties of organic compounds used in their active layers.
Innovation Solution
A light-receiving device is designed with a light-receiving layer containing a first and second organic compound, where the second compound has a higher HOMO level than the first, and specific absorption and carrier transport properties, enabling efficient hole and electron transport and detection of visible light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single organic compound is used in the active layer, then the device structure is simple, but the absorption spectrum coverage and carrier transport efficiency are insufficient for effective visible light detection
Solution Approach 1:
The patent employs a composite active layer comprising two different organic compounds: a first organic compound (e.g., rubrene) with high electron mobility and a second organic compound (e.g., m-MTDATA) with high hole mobility and appropriate absorption spectrum. This composite structure enables the device to detect visible light effectively by combining the complementary properties of both compounds, resolving the contradiction between absorption coverage and device simplicity.
2Productivity
If the HOMO level difference between organic compounds is large, then carrier transport efficiency is improved, but the energy alignment and charge generation efficiency deteriorate
Solution Approach 1:
The patent optimizes the HOMO level difference parameter between the two organic compounds to a specific range (0.2-1.5 eV). This parameter optimization ensures sufficient driving force for carrier transport while maintaining proper energy alignment for efficient charge generation. The LUMO level of the first compound is set to -3.5 to -2.5 eV, and the HOMO level difference is controlled to balance both transport efficiency and generation reliability.
3Adaptability or versatility
If organic compounds with broad absorption spectrum are used, then visible light detection capability is improved, but carrier transport properties deteriorate
Solution Approach 1:
The patent divides the active layer into two functional components with distinct roles: the first organic compound (rubrene) primarily provides high electron mobility and the second organic compound (m-MTDATA) provides high hole mobility and visible light absorption. This segmentation of functions allows each compound to be optimized for its specific role, achieving both good carrier transport properties and visible light detection capability simultaneously.
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 device effectively detects visible light by optimizing the HOMO level difference and carrier transport properties, enhancing its sensitivity and efficiency in converting incident light into electrical charge.
Implementation Method 1
An absorption spectrum of the first organic compound has one or more peaks. At least one peak wavelength of the peaks is greater than or equal to 400 nm and less than or equal to 700 nm.
Implementation Method 2
the photoelectric conversion element generates the image capturing signal
Data Source
AI summary
A light-receiving device with a novel structure is provided. The provided light-receiving device includes a light-receiving layer between a pair of electrodes. The light-receiving layer includes an active layer. The active layer contains a first organic compound and a second organic compound. An absorption spectrum of the first organic compound has one or more peaks. At least one peak wavelength of the peaks is greater than or equal to 400 nm and less than or equal to 700 nm. The HOMO level of the second organic compound is higher than the HOMO level of the first organic compound. The difference between the HOMO level of the first organic compound and the HOMO level of the second organic compound is preferably higher than or equal to 0.2 eV and lower than or equal to 1.5 eV and further preferably higher than or equal to 0.4 eV and lower than or equal to 1.5 eV.