Binary Image Sensor Quantum Dot Charge Storage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current image sensors face challenges in achieving performance improvements due to pixel size limitations, particularly when pixels are smaller than 1 μm, resulting in narrower dynamic range, smaller full well capacity, and lower signal-to-noise ratio (SNR).
Innovation Solution
A binary image sensor design incorporating unit pixels with quantum dots on a substrate, featuring a charge storage region between the gate electrode and the quantum dot, which stores carriers generated by incident light, and a column sense amplifier circuit to detect binary information, allowing for improved light collection efficiency and reduced crosstalk, enabling a wider dynamic range without the need for an analog-to-digital converter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If pixel size is reduced to achieve downsizing, then device area is reduced, but dynamic range and signal-to-noise ratio deteriorate
Solution Approach 1:
The pixel is segmented into distinct functional regions: a photoelectric conversion region containing quantum dots for light absorption, a charge storage region for accumulating generated carriers, and a readout circuit region. This segmentation allows each region to be optimized independently, enabling small pixel area while maintaining sufficient light collection capacity and signal quality through specialized charge storage.
Solution Approach 2:
The invention transitions from planar charge collection to three-dimensional charge storage by introducing a dedicated charge storage region beneath the photoelectric conversion region. This vertical dimension allows increased full well capacity and improved signal-to-noise ratio without increasing the lateral pixel area, effectively decoupling pixel size from light collection efficiency.
2Area of stationary object
If pixel size is reduced to achieve downsizing, then device area is reduced, but full well capacity deteriorates
Solution Approach 1:
The invention transitions from planar charge collection to three-dimensional charge storage by introducing a dedicated charge storage region beneath the photoelectric conversion region. This vertical dimension allows increased full well capacity and improved signal-to-noise ratio without increasing the lateral pixel area, effectively decoupling pixel size from light collection efficiency.
Solution Approach 2:
The charge storage region is nested beneath the photoelectric conversion region, creating a hierarchical structure where the storage region is contained within the vertical profile of the pixel. This nesting allows maximum utilization of the pixel volume for charge storage without increasing the lateral footprint, thereby maintaining small pixel area while increasing full well capacity.
3Reliability
If quantum dots are used to improve light collection efficiency, then light absorption improves, but manufacturing complexity increases
Solution Approach 1:
The invention utilizes quantum dots with tunable size parameters to control absorption characteristics. By adjusting the size and composition of quantum dots, the absorption spectrum can be optimized for different wavelength ranges without changing the fundamental device structure. This parameter-based tuning allows flexible optimization of light collection efficiency while maintaining compatibility with existing semiconductor manufacturing processes.
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 binary image sensor enhances light collection efficiency, reduces crosstalk, and achieves a wider dynamic range, improving image sensor performance by processing binary information from unit pixels, which can be applied in various multimedia devices.
Implementation Method 1
at least one quantum dot on the surface of the substrate... configured to store carriers therein that are generated by the quantum dot responsive to incident light
Data Source
AI summary
A binary image sensor includes a plurality of unit pixels on a substrate having a surface on which light is incident. At least one quantum dot is disposed on the surface of a substrate. A column sense amplifier circuit is configured to detect binary information of a selected unit pixel among the plurality of unit pixels from a voltage or a current detected from the selected unit pixel, and a processing unit is configured to process binary information of the respective unit pixels to generate pixel image information. Related devices and methods of operation are also discussed.