Organic Light-Absorption Layer for Image Sensor Sensitivity
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Solution Overview
Problem
Silicon photodiodes in image sensors have limited sensitivity due to small absorption areas, leading to reduced resolution and integration capabilities, prompting the need for alternative materials that can selectively absorb light across specific wavelength regions.
Innovation Solution
The use of organic light-absorption materials with tailored chemical structures, such as those represented by Chemical Formulas 1 and 2, in a layered configuration within the image sensor, allowing for enhanced light absorption and wavelength selectivity, with a light-absorption auxiliary layer compensating for the broader spectral profile of the primary light-absorption layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If silicon photodiodes are used to achieve high resolution, then pixel size can be reduced, but sensitivity deteriorates due to small absorption area
Solution Approach 1:
The patent uses organic light-absorption materials with tailored chemical structures (Chemical Formulas 1 and 2) that combine specific functional groups to achieve both small pixel compatibility and high light absorption efficiency. The composite molecular structure enables enhanced sensitivity while maintaining small pixel dimensions for high resolution.
Solution Approach 2:
The patent introduces a light-absorption auxiliary layer with specific chemical structure (Formula 1) positioned adjacent to the primary light-absorption layer (Formula 2). This auxiliary layer has tailored light-absorption characteristics that complement the primary layer, creating localized enhancement of sensitivity without increasing overall pixel size.
2Reliability
If organic light-absorption materials with tailored structures are used, then wavelength selectivity and sensitivity improve, but device structure complexity increases
Solution Approach 1:
The patent combines the photodiode and color filter functions into a single integrated organic light-absorption material system. The primary light-absorption layer (Formula 2) and auxiliary light-absorption layer (Formula 1) work together to provide both photodetection and wavelength filtering, eliminating separate color filter components and reducing overall device complexity.
Solution Approach 2:
The organic light-absorption materials serve multiple functions simultaneously: they act as photodetectors for signal generation, wavelength filters for spectral selection, and sensitivity enhancers through the auxiliary layer. This multi-functionality reduces the number of separate components needed in the device.
3Measurement precision
If a light-absorption auxiliary layer is added to improve wavelength selectivity, then external quantum efficiency improves, but device complexity increases
Solution Approach 1:
The patent optimizes the thickness ratio between the primary light-absorption layer (Formula 2) and auxiliary light-absorption layer (Formula 1) to achieve maximum external quantum efficiency. By carefully controlling the thickness parameters of each layer, the system achieves enhanced wavelength selectivity and detection efficiency while minimizing the additional complexity introduced by the layered structure.
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 the external quantum efficiency and wavelength selectivity of the image sensor, enabling higher sensitivity and reduced crosstalk, while potentially replacing both photodiodes and color filters, thus enhancing device integration and resolution.
Implementation Method 1
A photoelectronic device typically converts light into an electrical signal using photoelectronic effects
Implementation Method 2
an organic material that is capable of replacing silicon may have a high extinction coefficient, or light absorption power, and may selectively absorb light in a particular wavelength region depending on a molecular structure
Data Source
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AI summary
Example embodiments relate to a photoelectronic device that includes a first electrode, a light-absorption layer on the first electrode and including a first p-type light-absorption material and a first n-type light-absorption material, a light-absorption auxiliary layer on the light-absorption layer and including a second p-type light-absorption material or a second n-type light-absorption material that have a smaller full width at half maximum (FWHM) than the FWHM of the light absorption layer, a charge auxiliary layer on the light-absorption auxiliary layer, and a second electrode on the charge auxiliary layer, and an image sensor including the same.