Nano Antenna Pixel Structure for Low-Light Image Sensing
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Solution Overview
Problem
Image sensors in mobile devices struggle to capture clear images in low-light conditions due to low photoelectric conversion efficiency, resulting in dim night photography.
Innovation Solution
A pixel structure incorporating a nano antenna unit with a metal-insulator-metal diode at the nano gap, enhancing light field interaction and converting alternating current to direct current for improved photoelectric conversion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional image sensors are used, then the device structure remains simple, but photoelectric conversion efficiency is low under weak light conditions
Solution Approach 1:
The patent embeds a nano antenna unit within each pixel structure. The nano antenna unit includes multiple M parts with nano gaps between them, forming a nested configuration where the M parts are positioned within the pixel structure. This nesting approach increases photoelectric conversion efficiency by creating multiple interaction points for photons while maintaining a compact overall structure.
Solution Approach 2:
The patent introduces a vertical dimension by stacking M parts above the substrate unit cell. Instead of only horizontal arrangement, the M parts are positioned at different heights (e.g., first M part at first height, second M part at second height), creating a three-dimensional structure that enhances light field interaction and photoelectric conversion efficiency.
2Reliability
If more photons are captured to improve image quality in weak light, then photoelectric conversion efficiency increases, but the generated electrical signal remains weak
Solution Approach 1:
The patent combines multiple functional elements into an integrated nano antenna unit: M parts for light absorption, nano gaps for field enhancement, and metal-insulator-metal diodes for signal rectification. By merging these elements into a single unified structure, the system efficiently converts captured photons into stronger electrical signals while maintaining reliability in weak light conditions.
Solution Approach 2:
The patent changes the electrical signal parameters by introducing metal-insulator-metal diodes that rectify the generated alternating current into direct current. This parameter transformation (from AC to DC) strengthens the usable electrical signal while maintaining the ability to capture photons in weak light conditions.
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 structure significantly enhances photoelectric conversion efficiency under weak light conditions, allowing for clearer image capture in low-light environments.
Implementation Method 1
an enhanced light field is formed at the nano gap of the nano antenna
Implementation Method 2
electron tunneling occurs in the nano gap, and a function of a tunneling diode is achieved
Implementation Method 3
Both image sensors essentially utilize a particle nature of light and let photons excite free electrons in a semiconductor to generate an electrical signal
Data Source
AI summary
A pixel structure and an image sensor are provided, to improve photoelectric conversion efficiency under a weak light condition and resolve a problem that an image generated in weak light is dim. The pixel structure includes a metallic ground plane, and a substrate unit cell located on the metallic ground plane. The pixel structure further includes a nano antenna unit that is located on the substrate unit cell and that includes one or more nano antennas, each of the one or more nano antennas corresponding to one optical band and including M parts A nano gap is formed between the M parts, a metal-insulator-metal diode is formed at the nano gap, and M is a multiple of 2. The pixel structure further includes a packaging unit that covers the nano antenna unit. The image sensor includes a plurality of pixel structures.