Corner Cube Reflection Layer for Light Detection Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Long-wavelength light detection devices face issues with reduced quantum efficiency and optical color mixing due to components like wiring layers and interfaces, which existing technologies have not adequately addressed.
Innovation Solution
A light detection device with a substrate and a wiring layer where the reflection layer, including corner cube-shaped recesses, overlaps the photoelectric conversion units to retroreflect long-wavelength light back to its original pixel, preventing crosstalk and improving quantum efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pixel separation unit is provided between photoelectric conversion units to reflect incident light, then quantum efficiency is improved and optical color mixing is suppressed, but the improvement is insufficient because components like wiring layers and interfaces dominate the reflection
Solution Approach 1:
The invention transitions from two-dimensional pixel separation (in the plane) to three-dimensional corner cube reflectors (adding depth dimension). The corner cube structure extends the reflection mechanism into the stacking direction, creating a volumetric solution that addresses the insufficiency of planar pixel separation units.
Solution Approach 2:
The corner cube reflectors are positioned specifically at locations where long-wavelength light reflection is most problematic (near wiring layers and interfaces), providing localized enhancement of light reflection exactly where needed rather than uniform treatment across all pixels.
2Reliability
If long-wavelength light is incident on a photoelectric conversion unit, then light detection is achieved, but the light passes through to adjacent units causing reduced quantum efficiency and optical color mixing
Solution Approach 1:
The invention converts the harmful effect of light transmission (which causes crosstalk) into a beneficial effect by using the transmitted light to illuminate the corner cube reflectors, which then retroreflect the light back to the original photoelectric conversion unit, turning energy loss into useful signal enhancement.
Solution Approach 2:
The corner cube reflector acts as an intermediary element between the photoelectric conversion unit and the transmitted light, capturing the light that would otherwise be lost and returning it to the source, thereby mediating the energy flow to improve overall system efficiency.
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 solution effectively suppresses optical color mixing and enhances quantum efficiency by ensuring long-wavelength light is absorbed by its original photoelectric conversion unit, improving the overall performance of light detection devices.
Implementation Method 1
the reflection layer includes a plurality of recesses each including a corner cube-shaped portion in each of portions overlapping the photoelectric conversion units on a surface on a side of the photoelectric conversion units
Data Source
AI summary
Provided is a light detection device capable of suppressing optical color mixing while improving quantum efficiency QE. A substrate including a plurality of photoelectric conversion units and a wiring layer arranged on a side opposite to a light receiving surface of the substrate are provided. Then, the wiring layer includes a reflection layer formed so as to overlap at least a part of the plurality of photoelectric conversion units in a stacking direction in which the substrate and the wiring layer are stacked. Furthermore, the reflection layer includes a plurality of recesses each including a corner cube-shaped portion in each of portions overlapping the photoelectric conversion units on a surface on a side of the photoelectric conversion units.