Imaging Device Light-Shielding Body Fluorescence Noise Reduction
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Solution Overview
Problem
Imaging devices with photoelectric conversion layers containing semiconductor quantum dots and coating materials suffer from increased noise due to fluorescence emitted from the coating materials, which is absorbed by charge storage regions and control circuits, causing image blurring, color mixing, and noise.
Innovation Solution
Incorporating light-shielding bodies within or above the photoelectric conversion layer, specifically designed to absorb or reflect light in the wavelength ranges corresponding to the absorption and fluorescence emissions of the coating materials, thereby reducing the amount of fluorescence that reaches the semiconductor substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If coating material is used to cover semiconductor quantum dots, then the quantum dots are protected and electrical conduction is improved, but fluorescence is emitted that causes noise in the imaging device
Solution Approach 1:
A light-shielding body is introduced as an intermediary component between the coating material and the charge storage regions. This light-shielding body selectively blocks fluorescence wavelengths while allowing photoelectric conversion light to pass through, thus preventing the harmful fluorescence from reaching the charge storage regions without interfering with the primary photoelectric conversion function
Solution Approach 2:
The optical path is segmented into different wavelength channels by introducing the light-shielding body that selectively filters specific wavelength ranges. The light-shielding body is positioned at specific locations (above the photoelectric conversion layer or within the semiconductor substrate) to create wavelength-selective pathways that separate useful light from harmful fluorescence
2Object-generated harmful factors
If light-shielding body is added to block fluorescence, then noise is reduced, but device complexity increases
Solution Approach 1:
The light-shielding body is designed to serve multiple functions: it blocks fluorescence wavelengths while maintaining transparency to photoelectric conversion wavelengths, and can be integrated with existing device components such as the counter electrode or semiconductor substrate, thus reducing the need for separate additional components
Solution Approach 2:
The light-shielding body utilizes wavelength-selective optical parameters to differentiate between useful light and harmful fluorescence. By controlling the absorption and transmission characteristics at different wavelengths, the device can selectively block harmful wavelengths while preserving the useful photoelectric conversion process
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 implementation of light-shielding bodies significantly reduces noise in the imaging device by minimizing the absorption of fluorescence by charge storage regions and control circuits, leading to improved image quality and reduced noise levels.
Implementation Method 1
a coating material that covers the semiconductor quantum dots and that has a property of absorbing light in a second wavelength range and emitting fluorescence in a third wavelength range
Implementation Method 2
The at least one first light-shielding body absorbs or reflects light with a wavelength in at least part of the second wavelength range
Implementation Method 3
semiconductor quantum dots having a property of absorbing light in a first wavelength range
Data Source
AI summary
An imaging device includes: a semiconductor substrate; a plurality of pixel electrodes located above the semiconductor substrate and each electrically connected to the semiconductor substrate; a counter electrode located above the plurality of pixel electrodes; a first photoelectric conversion layer located between the counter electrode and the plurality of pixel electrodes; and at least one first light-shielding body located in the first photoelectric conversion layer or above the first photoelectric conversion layer. The first photoelectric conversion layer contains semiconductor quantum dots that absorb light in a first wavelength range and a coating material that covers the semiconductor quantum dots, the coating material absorbing light in a second wavelength range, the coating material emitting fluorescence in a third wavelength range. The at least one first light-shielding body absorbs or reflects light with a wavelength in at least part of the second wavelength range.