Photodiode Color Filter Structure for Stray Light Redistribution
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Solution Overview
Problem
Light sensing elements face inaccuracies due to refraction and stray light from layers above photodiodes, leading to imprecise light detection.
Innovation Solution
Incorporating a hollow light host structure above photodiodes with a higher refractive index than the color filter, which uniformly redistributes incident light, ensuring balanced light distribution and improved accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If light passes through layers above photodiodes, then light detection is enabled, but refraction and stray light cause imprecise light measurement
Solution Approach 1:
The patent introduces a light host structure as an intermediary element between the color filter and photodiode. This light host has a higher refractive index than the color filter, serving as a mediator to redirect and concentrate stray light toward the photodiode, thereby improving light sensing accuracy while enabling light detection to proceed
Solution Approach 2:
The patent changes the refractive index parameter by selecting a light host material with a higher refractive index than the color filter material. This parameter change enables the light host to effectively redirect light paths, converting harmful refraction and stray light into useful light concentration at the photodiode, thus improving measurement precision
2Measurement precision
If a light host structure is added above photodiodes, then light distribution uniformity is improved, but device complexity increases
Solution Approach 1:
The patent merges the light host structure with the existing color filter layer, where the light host is embedded within or integrated to the color filter. This combining approach improves light distribution uniformity while minimizing the increase in device complexity by utilizing the existing layer structure rather than adding completely separate components
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 hollow light host structure effectively redirects incident light to photodiodes, enhancing light distribution uniformity and improving the accuracy of light sensing elements.
Implementation Method 1
a refractive index of the first light host is higher than that of the color filter, and the refractive index of the first light host is in a range of 1.8 to 2.5
Data Source
AI summary
The present disclosure provides a light sensing element including a unit. The unit includes a plurality of photodiodes, a color filter disposed above the photodiodes, and a light host embedded in the color filter. The light host is a hollow structure disposed above the photodiodes. The color filter includes a first portion surrounding the light host, a second portion surrounded by the light host, and a third portion covering and physically contacting the first portion, the light host, and the second portion.