Ferroelectric Heterojunction for Wide-Range Low-Power Optical Sensing
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Solution Overview
Problem
Existing digital image sensors face challenges in detecting a wide wavelength range, consuming high power, and being large and costly, while also failing to meet the demands of low power consumption and high response in the future Internet of Things (IoT).
Innovation Solution
A heterojunction structure device is proposed, comprising a gate electrode, a ferroelectric layer made of hafnium zirconium oxide (HZO), and a channel layer made of alpha-indium selenide (α-In2Se3), with an insulating layer of aluminum oxide (Al2O3) in between. This device allows for control of polarization by light irradiation and voltage applied to the gate electrode, enabling all optical signal sensing, processing, and memory within a single device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional CMOS image sensors or CCD cameras are used to detect optical signals, then digital image capturing is achieved, but the device cannot detect a wide (Vis-NIR) wavelength range and consumes considerable power
Solution Approach 1:
The patent merges multiple functions (detection, processing, and memory) into a single neuromorphic vision system device. By integrating the ferroelectric layer for memory and the semiconductor layer for detection and processing in one heterostructure, the system eliminates the need for separate modules, thereby reducing power consumption while maintaining wide wavelength detection capability through the semiconductor material properties
Solution Approach 2:
The neuromorphic vision system device performs multiple functions simultaneously: optical signal detection by the semiconductor layer, signal processing through neuromorphic computation, and memory storage via the ferroelectric layer. This multi-functional integration allows the single device to replace traditional multi-module systems, reducing overall power consumption while detecting a wide wavelength range
2Measurement precision
If existing digital image sensors are used, then image detection is achieved, but the device is large in size and incurs high cost
Solution Approach 1:
The patent combines detection, processing, and memory functions into a single integrated device with a compact heterostructure. The layered design (ferroelectric layer + semiconductor layer) achieves high functionality in a minimal footprint, dramatically reducing device area compared to traditional multi-module systems while maintaining precise optical signal detection across wide wavelengths
3Productivity
If conventional separate memory and processing apparatuses are used, then data processing is achieved, but the system consumes high power and is too large for practical application
Solution Approach 1:
The patent merges memory (ferroelectric layer) and processing (semiconductor layer with neuromorphic functionality) into a single integrated device. This eliminates the need for separate memory and processing apparatuses, reducing system complexity and size while maintaining high data processing capability through in-memory computation and neuromorphic operations
4Extent of automation
If traditional digital computing systems are used for artificial intelligence, then logic operations are achieved, but the system cannot meet low power consumption and high response requirements
Solution Approach 1:
The neuromorphic vision system implements self-learning and self-adaptation capabilities through the inherent properties of the ferroelectric layer (non-volatile memory, threshold switching) and semiconductor layer (photodetection, carrier dynamics). The system performs autonomous neuromorphic computation without requiring external power-intensive processing, achieving self-service operation that meets low power consumption and high response requirements
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 heterojunction structure device achieves efficient detection and processing of optical signals across a wide wavelength range, including weak light intensities, while reducing power consumption and device size, making it suitable for applications in artificial visual systems and other IoT devices.
Implementation Method 1
control of polarization by light irradiation
Implementation Method 2
spontaneous electric dipole polarization and movement of domain walls under external electric field
Implementation Method 3
movement of domain walls under external electric field, mechanical deformation
Implementation Method 4
the optical response of such a system is mostly handled by band-to-band transition
Data Source
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AI summary
Provided is a heterojunction structure device. The heterojunction structure device includes: a gate electrode (200) disposed on a substrate (100); a ferroelectric layer (300) disposed on the gate electrode and including a material having ferroelectric characteristics; an insulating layer (400) on the ferroelectric layer; a channel layer (500) disposed on the insulating layer and including a material having ferroelectric and semiconductor characteristics; and a source electrode (S) and a drain electrode (D) disposed on the channel layer while being spaced apart from each other.