Organic Photodiode Sensor Using Single-Layer Energy Alignment
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Solution Overview
Problem
Existing sensors with organic photodiodes face challenges in implementing desired electrical characteristics due to difficulties in matching material properties and processability of semiconductors forming a pn junction.
Innovation Solution
A sensor design incorporating a single organic photoelectric conversion layer with a specific organic light absorption semiconductor, a hole auxiliary layer, and an electron auxiliary layer, with carefully controlled energy levels and bandgaps, eliminates the need for a pn junction, enhancing processability and electrical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a pn junction is formed using two or more semiconductors with different electrical properties, then wavelength selectivity can be achieved, but material property matching and processability become difficult
Solution Approach 1:
The patent extracts and eliminates the pn junction structure from the organic photodiode, replacing it with a single semiconductor layer design. This removes the complex interface matching requirements between different semiconductors while maintaining wavelength selectivity through the molecular structure of the single semiconductor material used in the photoelectric conversion layer.
Solution Approach 2:
The patent changes the structural parameter from a pn junction (requiring multiple semiconductors with different electrical properties) to a single semiconductor layer. This parameter change simplifies material selection and processing while achieving the same functional outcome through optimized molecular structure and energy level alignment.
2Measurement precision
If a pn junction is formed using two or more semiconductors with different electrical properties, then wavelength selectivity can be achieved, but processability becomes difficult
Solution Approach 1:
The patent removes the pn junction structure that requires multiple semiconductor materials with different processing characteristics. By using a single semiconductor material for the photoelectric conversion layer, the manufacturing process becomes simpler and more controllable, eliminating the need to match and coordinate multiple material processing parameters.
Solution Approach 2:
The patent changes the structural approach from a pn junction (multiple materials requiring coordinated processing) to a single semiconductor layer design. This parameter change consolidates processing requirements into a single material system, significantly improving processability while maintaining wavelength selectivity through molecular design.
3Reliability
If multiple semiconductors with different electrical properties are used, then desired electrical characteristics can be achieved, but reliability decreases due to material matching difficulties
Solution Approach 1:
The patent extracts and eliminates the pn junction interface that creates reliability issues through material property mismatches. By using a single semiconductor material throughout the photoelectric conversion layer, the patent removes the source of interfacial defects and electrical instability, thereby improving reliability while simplifying material selection.
Solution Approach 2:
The patent changes the structural parameter from a pn junction (requiring precise material property matching for reliability) to a single semiconductor layer. This parameter change eliminates the complexity of coordinating multiple material properties, leading to more consistent and reliable electrical characteristics across different devices.
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 solution results in improved reliability, consistency, and efficiency of the sensor by stabilizing hole and electron transfer, allowing for predictable electrical characteristics and reduced power consumption.
Implementation Method 1
Silicon photodiodes may be configured to absorb light in a wide wavelength spectrum and convert the absorbed light into electrical signals
Implementation Method 2
Organic materials may be configured to selectively absorb light of a specific wavelength spectrum depending on their molecular structure
Implementation Method 3
a difference between the HOMO energy level of the organic light absorption semiconductor and the HOMO energy level of the hole auxiliary material may be in a range of greater than 0 eV and less than about 1.00 eV, and a difference between a work function of the cathode and a LUMO energy level of the organic light absorption semiconductor is less than about 1.00 eV
Data Source
AI summary
A sensor includes an anode, a cathode, an organic photoelectric conversion layer between the anode and the cathode and including one type of organic light absorption semiconductor as a photoelectric conversion material and not including any other type of organic light absorption semiconductor, and a hole auxiliary layer between the anode and the organic photoelectric conversion layer and including a hole auxiliary material. An energy bandgap of the organic light absorption semiconductor is about 1.90 to about 2.20 eV. A HOMO energy level of the organic light absorption semiconductor is the same as or deeper than a HOMO energy level of the hole auxiliary material. A difference between the HOMO energy levels is greater than 0 eV and less than about 1.00 eV. A difference between a work function of the cathode and a LUMO energy level of the organic light absorption semiconductor is less than about 1.00 eV.