Organic Image Sensor Pixels with Stacked Wavelength Layers
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Solution Overview
Problem
Image sensors face challenges in achieving high resolution and small size while maintaining sensitivity, as smaller pixels result in reduced absorption areas.
Innovation Solution
The image sensor design incorporates multiple photo-sensing devices sensitive to different wavelength regions (blue, red, green, and white light) with organic light-absorbing materials and a semiconductor substrate, along with a color filter layer, to enhance light absorption and sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the pixel size is reduced to achieve smaller image sensor size and higher resolution, then the absorption area is reduced, but sensitivity deteriorates
Solution Approach 1:
The photo-sensing device is segmented into multiple independent photo-sensing units, each with its own light-absorbing material layer optimized for specific wavelength regions. This segmentation allows each unit to maximize light absorption efficiency independently, compensating for the reduced pixel size and maintaining sensitivity despite smaller absorption area.
Solution Approach 2:
The invention employs composite light-absorbing materials with different bandgap energies arranged in multiple layers. Each layer material is specifically selected to absorb different wavelength regions of light, creating a composite structure that enhances overall light absorption efficiency in compact pixels, thereby maintaining sensitivity while achieving high resolution.
2Reliability
If multiple photo-sensing devices with different wavelength sensitivities are integrated, then light-absorptive efficiency increases, but device complexity increases
Solution Approach 1:
Multiple photo-sensing devices sensitive to different wavelength regions are merged into a single integrated photo-sensing unit structure. The light-absorbing material layers are stacked vertically within the same pixel area, combining multiple wavelength detection capabilities in one compact unit, which increases light-absorptive efficiency without proportionally increasing device complexity.
Solution Approach 2:
The invention transitions from horizontal arrangement of multiple photo-sensing devices to vertical stacking in the depth dimension. Different light-absorbing material layers are arranged in vertical layers, each targeting specific wavelength regions. This dimensional change allows multiple wavelength sensitivities to be integrated within the same planar pixel area, increasing efficiency while controlling structural complexity.
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 increases light-absorptive efficiency, reduces light loss, and improves the overall sensitivity of the image sensor, enabling high-resolution imaging while maintaining a compact size.
Implementation Method 1
A photoelectric device converts light into an electrical signal using photoelectric effects
Implementation Method 2
a photoactive layer between the pair of light-transmitting electrodes and including an organic light-absorbing material
Implementation Method 3
a color filter layer on the semiconductor substrate and including a blue filter selectively absorbing light in the blue wavelength region, a red filter selectively absorbing light in the red wavelength region, and a green filter selectively absorbing light in the green wavelength region
Data Source
AI summary
Image sensors, and electronic devices including the same, include a first photo-sensing device sensing light in a full visible to near infrared ray region, a second photo-sensing device sensing light in a blue wavelength region, a third photo-sensing device sensing light in a red wavelength region, and a fourth photo-sensing device sensing light in a green wavelength region. At least one of the first photo-sensing device, the second photo-sensing device, the third photo-sensing device, and the fourth photo-sensing device includes a pair of light-transmitting electrodes facing each other, and a photoactive layer between the light-transmitting electrodes. The photoactive layer includes an organic light-absorbing material.