Pixel Splitter Structure for Higher Photodiode Conversion Efficiency
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Solution Overview
Problem
The conversion efficiency of photodiodes in electronic devices is reduced due to light absorption by filters in existing pixel structures, which leads to energy loss when incident light passes through the filter.
Innovation Solution
A pixel structure is designed with a splitter comprising stacked optical layers with different transmissivity regions, splitting incident light into multiple bands that are directed to corresponding light-receiving regions, thereby minimizing energy loss and enhancing photodiode conversion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a filter is used in the pixel structure to filter incident light, then the quality of light received by the photodiode is improved, but the filter absorbs a part of the incident light, reducing the conversion efficiency of the photodiode
Solution Approach 1:
The patent extracts and removes the filter component from the pixel structure. By eliminating the filter, the system avoids the energy absorption and conversion efficiency loss that filters cause, while still achieving the desired light reception quality through alternative optical design
Solution Approach 2:
The optical layer is designed to perform multiple functions simultaneously: it guides incident light to the photodiode, filters specific wavelengths through its material properties, and maintains high conversion efficiency. This multi-functional design eliminates the need for a separate filter component that would cause energy loss
2Reliability
If the pixel structure includes a microlens structure, filter, and photodiode stacked together, then the light guidance and filtering function is achieved, but the structure complexity increases and energy loss occurs due to filter absorption
Solution Approach 1:
The patent merges the filtering function into the optical layer itself rather than using a separate filter component. The optical layer combines light guidance and wavelength filtering in a single integrated structure, reducing the number of stacked components and simplifying the overall pixel structure
Solution Approach 2:
The optical layer is designed as a multi-functional component that simultaneously performs light guidance, focusing, and spectral filtering. This universal component replaces multiple separate elements (microlens and filter), reducing structural complexity while maintaining all necessary functions
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 solution improves the energy received by light-receiving regions, resulting in higher conversion efficiency of the photodiode and reduced energy loss, enhancing the overall performance of image sensor chips and camera modules.
Implementation Method 1
the first optical layer includes a first light-transmitting region and a second light-transmitting region, and the second optical layer includes a third light-transmitting region and a fourth light-transmitting region. Transmissivity of the first light-transmitting region and transmissivity of the second light-transmitting region are different, transmissivity of the third light-transmitting region and transmissivity of the fourth light-transmitting region are different, beams on different bands are formed after incident light passes through the splitter
Implementation Method 2
the pixel structure includes a microlens structure, a filter, and a photodiode, and the microlens structure, the filter, and the photodiode are stacked. the incident light may pass through the microlens structure, then passes through the filter, and is finally irradiated on the photodiode, so that the photodiode can convert an optical signal into an electrical signal
Data Source
AI summary
This application provides a pixel structure, an image sensor chip, and an electronic device. The pixel structure includes a splitter and a photodiode. The photodiode includes a light-receiving surface, the light-receiving surface includes a plurality of light-receiving regions, and the splitter faces the light-receiving surface. The splitter includes a first optical layer and a second optical layer stacked, the first optical layer includes a first light-transmitting region and a second light-transmitting region, and the second optical layer includes a third light-transmitting region and a fourth light-transmitting region. Transmissivity of the first light-transmitting region and transmissivity of the second light-transmitting region are different, and transmissivity of the third light-transmitting region and transmissivity of the fourth light-transmitting region are different. A projection of the first light-transmitting region and a projection of the third light-transmitting region do not overlap in a direction perpendicular to the first optical layer.