Plasmon-Filter Electromagnetic Detector for Selective Wavelength Sensing
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Solution Overview
Problem
Conventional electromagnetic wave detectors using graphene have low absorptivity and are limited to detecting electromagnetic waves with energy greater than or equal to the band gap of the semiconductor layer, making it difficult to selectively detect specific wavelength bands and enhance sensitivity.
Innovation Solution
An electromagnetic wave detector incorporating a photoelectric conversion element and a plasmon filter with periodically arranged through-holes, where a two-dimensional material layer and semiconductor layer form a Schottky junction, enhancing sensitivity by generating surface plasmon resonance for selective wavelength detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a graphene layer and semiconductor layer form a Schottky junction for detection, then the detector can operate with voltage control, but the detection is limited to electromagnetic waves with energy greater than or equal to the band gap of the semiconductor layer, making it difficult to selectively detect specific wavelength bands
Solution Approach 1:
The detector is divided into two functional parts: a plasmon filter layer for wavelength selection and a photoelectric conversion element for detection. The plasmon filter layer contains through-holes with specific patterns that selectively transmit certain wavelength bands, while the photoelectric conversion element detects the transmitted electromagnetic waves. This segmentation allows independent optimization of wavelength selectivity and detection functionality.
Solution Approach 2:
The plasmon filter layer acts as an intermediary between the incident electromagnetic waves and the photoelectric conversion element. It selectively filters the wavelength bands before they reach the detector, enabling wavelength-specific detection while maintaining the voltage-controlled operation of the Schottky junction.
2Speed
If graphene is used as the electromagnetic wave detection layer, then high mobility is achieved, but the absorptivity is extremely low at only 2.3%, making it difficult to increase detection sensitivity
Solution Approach 1:
The detector uses a composite structure combining a plasmon filter layer (which can be metal or dielectric material) with a photoelectric conversion element containing a two-dimensional material layer and semiconductor layer. This composite structure leverages the high mobility of two-dimensional materials while using the plasmon filter to enhance light absorption through localized surface plasmon resonance, thereby improving detection sensitivity without sacrificing carrier mobility.
3Ease of operation
If at least two dielectric layers are provided on an n-type semiconductor layer with graphene formed on them, then a Schottky junction is formed for voltage-controlled detection, but the sensitivity depends on quantum efficiency of the semiconductor layer which limits further sensitivity enhancement
Solution Approach 1:
The invention changes the structural parameters of the detector by introducing a plasmon filter layer with specific through-hole patterns before the photoelectric conversion element. This structural modification enables localized surface plasmon resonance, which enhances the quantum efficiency of photoelectric conversion and thereby improves detection sensitivity while maintaining voltage-controlled operation through the Schottky junction.
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 selective detection of electromagnetic waves in specific wavelength bands by increasing quantum efficiency and photocarrier generation.
Implementation Method 1
a plasmon filter disposed so as to be opposite to the at least one photoelectric conversion element. A plurality of through-holes are periodically made in the plasmon filter
Implementation Method 2
an electromagnetic wave detector including a photoelectric conversion element and a plasmon filter... a two-dimensional material layer that is disposed on the other portion of the region and the insulating layer and electrically connected to the other portion of the region
Data Source
AI summary
An electromagnetic wave detector includes at least one photoelectric conversion element and a plasmon filter disposed so as to be opposite to the at least one photoelectric conversion element. A plurality of through-holes are periodically made in the plasmon filter. The at least one photoelectric conversion element includes a semiconductor layer including a region overlapping with at least one through-hole in the plurality of through-holes in planar view, an insulating layer formed so as to cover a part of the region, a two-dimensional material layer that is disposed on the other portion of the region and the insulating layer and electrically connected to the other portion of the region, a first electrode portion electrically connected to the two-dimensional material layer, and a second electrode portion electrically connected to the semiconductor layer.