Carbon Nanotube Oxide Metal Diodes for THz Rectenna Scalability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current IR detectors and rectennas face challenges in efficiently collecting and converting energy at room temperature using lightweight and inexpensive materials, particularly in achieving scalable and robust manufacturing methods for nanostructure-based diodes that operate effectively at THz frequencies.
Innovation Solution
Carbon nanostructure-oxide-metal diodes, such as carbon nanotube-oxide-metal diodes, are developed with vertically aligned multiwall carbon nanotubes coated with a dielectric layer and metal contacts, enabling high asymmetry, non-linearity, and energy conversion efficiency at low turn-on voltages and across a broad temperature range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional rectenna structures are used for IR detection, then device functionality is achieved, but manufacturing scalability and robustness are limited
Solution Approach 1:
The device is segmented into vertically stacked functional layers (carbon nanotube layer, dielectric layer, metal electrode layer) that can be independently optimized and manufactured. This segmentation enables scalable production while maintaining device robustness through standardized layer interfaces.
Solution Approach 2:
The invention uses composite structures combining carbon nanotubes with dielectric materials and metal electrodes to create a multi-material system that leverages the advantages of each material type for scalable and robust manufacturing.
2Measurement precision
If nanostructure-based diodes are used to enable quantum mechanical tunneling at THz frequencies, then detection capability is improved, but fabrication of small diode geometries over large areas becomes difficult
Solution Approach 1:
The invention transitions from planar diode geometries to vertically stacked three-dimensional structures, enabling quantum mechanical tunneling functionality while facilitating large-area manufacturing through vertical integration rather than lateral patterning.
Solution Approach 2:
The invention changes the geometric parameters from sub-micron lateral dimensions to vertical stacking with controllable layer thicknesses, making the device dimensions more amenable to standard thin-film deposition techniques and large-area fabrication.
3Use of energy by moving object
If carbon nanotubes are used for antenna-like interactions with electromagnetic radiation, then energy collection capability is improved, but efficient energy extraction through diodes remains challenging
Solution Approach 1:
A dielectric layer is introduced as an intermediary between the carbon nanotube antenna and metal electrode, enabling efficient charge separation and energy extraction while maintaining the antenna-like electromagnetic interactions of the carbon nanotubes.
Solution Approach 2:
The dielectric layer is positioned to preliminarily separate charges at the carbon nanotube-metall interface before current flows, improving energy extraction efficiency by pre-establishing the electric field necessary for efficient charge collection.
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 carbon nanostructure-oxide-metal diodes exhibit improved energy collection and conversion capabilities, with rectification ratios and current densities maintained across varying temperatures, demonstrating potential for efficient IR detection and solar energy conversion.
Implementation Method 1
fabricating the small diode geometries required to enable operation by quantum mechanical tunneling at THz frequencies
Implementation Method 2
the multiwall CNTs exhibited both polarization and the length antenna effects that could be used in rectennas for IR and optical detection and solar harvesting applications
Implementation Method 3
arrays containing carbon nanostructure-oxide-metal diodes... exhibit high asymmetry and non-linearity... and a rectification ratio of at least about 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60
Data Source
AI summary
Arrays containing carbon nanostructure-oxide-metal diodes, such as carbon nanotube (CNT)-oxide-metal diodes and methods of making and using thereof are described herein. In some embodiments, the arrays contain vertically aligned carbon nanostructures, such as multiwall carbon nanotubes (MWCNTs) coated with a conformal coating of a dielectric layer, such as a metal oxide. The tips of the carbon nanostructures are coated with a low work function metal, such as a calcium or aluminum to form a nanostructure-oxide-metal interface at the tips. The arrays can be used as rectenna at frequencies up to about 40 petahertz because of their intrinsically low capacitance. The arrays described herein produce high asymmetry and non-linearity at low turn on voltages down to 0.3 V and large current densities up to about 7,800 mA/cm2 and a rectification ratio of at least about 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60.