Electromagnetic Wave Detector with 2D Material Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electromagnetic wave detectors using two-dimensional material layers like graphene face challenges in achieving high sensitivity and OFF operation due to limitations in amplifying optical carriers and quantum efficiency in Schottky operation.
Innovation Solution
An electromagnetic wave detector design incorporating a light-receiving element with a pn junction, an insulating film, and a two-dimensional material layer where the two-dimensional material layer extends onto the insulating film, allowing for enhanced electrical connection and amplification of photocurrent through an optical gate effect, enabling high sensitivity and OFF operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a source-drain voltage is applied to the graphene layer to enable high sensitivity operation, then the detection sensitivity is improved, but the OFF operation becomes difficult to achieve
Solution Approach 1:
The patent segments the voltage application into two independent paths: a gate voltage applied between the gate electrode and source electrode to control channel conductivity, and a small source-drain voltage applied between source and drain electrodes for carrier extraction. This segmentation allows the gate voltage to enable OFF operation by depleting carriers, while the source-drain voltage maintains sensitivity without preventing the OFF state.
2Ease of operation
If a voltage is applied between the gate electrode and source electrode or drain electrode to enable OFF operation, then the OFF operation is achieved, but the sensitivity becomes dependent on quantum efficiency which limits amplification
Solution Approach 1:
The patent introduces an insulating film as an intermediary between the light-receiving element and the two-dimensional material layer. This insulating film with a specific dielectric constant acts as a mediator that transmits the electric field from the light-receiving element to the two-dimensional material layer, enabling the optical gate effect to amplify photocurrent while maintaining OFF operation capability through gate voltage control.
3Ease of operation
If the detector operates in Schottky operation mode, then the OFF operation is enabled, but the optical carrier amplification is insufficient and sensitivity cannot be increased
Solution Approach 1:
The patent employs a composite structure combining a light-receiving element (semiconductor), an insulating film (dielectric material), and a two-dimensional material layer (graphene or similar). This composite structure integrates the advantages of each material: the light-receiving element generates optical carriers, the insulating film transmits electric fields with enhanced dielectric properties, and the two-dimensional material layer provides high mobility for carrier extraction and amplification, achieving both OFF operation and high sensitivity.
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 detector achieves high detection sensitivity and capable OFF operation by amplifying photocurrent through the optical gate effect, exceeding quantum efficiency and response speed limitations of conventional detectors.
Implementation Method 1
amplifying photocurrent through an optical gate effect
Implementation Method 2
a light-receiving element, an insulating film, a two-dimensional material layer where the two-dimensional material layer extends onto the insulating film, allowing for enhanced electrical connection and amplification of photocurrent
Data Source
AI summary
An electromagnetic wave detector includes a light-receiving element, an insulating film, a two-dimensional material layer, a first electrode part, and a second electrode part. The light-receiving element includes a first semiconductor portion of a first conductivity type and a second semiconductor portion. The second semiconductor portion is joined to the first semiconductor portion. The second semiconductor portion is of a second conductivity type. The insulating film is disposed on the light-receiving element. The insulating film has an opening portion. The two-dimensional material layer is electrically connected to the first semiconductor portion in the opening portion. The two-dimensional material layer extends from on the opening portion onto the insulating film. The first electrode part is disposed on the insulating film. The first electrode part is electrically connected to the two-dimensional material layer. The second electrode part is electrically connected to the second semiconductor portion.