Hongke case | nanogue uses Onyx system to realize nondestructive characterization of graphene electrical properties

Challenge ： high resolution 、 Rapid and nondestructive characterization of graphene

Two dimensional material , It means that electrons can only be in the nano scale of two dimensions （1-100nm） Free movement on （ Plane motion ） The material of , Such as nano film 、 Superlattice 、 Quantum well . Two dimensional materials are accompanied by 2004 University of Manchester Geim The team successfully separated the graphite material with single atomic layer —— graphene （graphene） Proposed .

graphene （Graphene） Is a kind of sp² The hybrid connected carbon atoms are closely packed into a single-layer two-dimensional cellular lattice structure , It is the thinnest and hardest nano material in the world , It's almost completely transparent , Only absorb 2.3% Light ; The thermal conductivity is as high as 5300 W/m·K, Higher than carbon nanotubes and diamonds , Harder than diamonds , The strength is higher than the best steel in the world 100 times , Its electron mobility at room temperature is higher than 15000 cm2/V·s, Compared with carbon nanotubes or silicon crystals （monocrystalline silicon） high , And the resistivity is only about 10-6 Ω·cm, Lower than copper or silver , It's the least resistivity material in the world . Because its resistivity is very low , Electrons move very fast , So it's expected to be used to develop thinner 、 A new generation of electronic components or transistors that conduct electricity faster .

Because graphene has excellent optics 、 electrical 、 Mechanical properties , It's in material science 、 Micro nano processing 、 energy 、 Biomedicine and drug delivery have important application prospects , Is considered a revolutionary material in the future .

CIC nanoGUNE It was founded on 2009 Spanish research center , Its mission is to solve the basic and applied research of nanoscience and nanotechnology , Promote the education and training of senior researchers in this field , Graphene is one of the key materials in their research . in addition to ,Graphenea yes nanoGUNE Our first start-up , Committed to the manufacturing of industrial graphene .

Usually , Before using materials such as graphene , The most important thing is to measure various parameters of materials through various characterization techniques, so as to judge the properties and quality of materials . Usually for large area materials , The conductivity of the tested sample can be obtained by using the four probe method , Simple operation and fast detection , But you must contact the sample , This may cause damage to the sample . And for nanoscale materials , Commonly used Raman spectroscopy 、AFM and TEM The method can obtain a resolution of up to nm Level image , However, this requires sample preparation steps and a long scanning time .

therefore , about nanoGUNE In terms of material research , What they need is a fast system to detect materials with different properties , Without destroying them and with high accuracy . On the other hand ,Graphenea Hope to test materials , In order to control the quality of graphene manufacturing process and develop new advanced materials . Both are looking for a solution , At high resolution 、 Contactless 、 Non destructive and fast way to characterize blocky 、 Film and 2D material （ Like graphene ） Electrical performance of （ Such as conductance 、 Resistance or carrier mobility ）.

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Hongke solutions ： Terahertz Onyx System

Terahertz provided by Hongke Onyx System is nanoGUNE and Graphenea The perfect solution .

Based on terahertz spectrum technology Onyx yes The first one on the market aims to realize graphene by terahertz wave 、 Film and others 2D A system for nondestructive characterization of materials in the whole region , It fills the gap between macro and nano scale characterization tools , The detection area can be from 0.5 mm2 To a larger area (m2), Can be at the highest 50um The spatial resolution of Rapid characterization  (12cm2/min) Large area sample , It promotes the industrialization of material research .

ONYX The system is based on terahertz spectrum technology , The time domain signal of the interaction between the emitted terahertz wave and the material is collected , Then it is transformed into spectrum signal by Fourier transform , The optical parameters of the measured sample can be obtained by analyzing the spectrum data of this signal and the reference signal , Include conductivity 、 Resistivity 、 Charge carrier mobility 、 Charge carrier density 、 Refractive index and substrate thickness . These parameters Only one measurement is needed to get all , There is no need for sample preparation and long scanning time , It realizes simple and high-speed measurement .

Onyx The system conforms to IEC TS 62607-6-10：2021 The technical specification , This specification covers the measurement of sheet resistance of graphene based materials using terahertz time domain spectroscopy .

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result ： Fast and reliable tools , Help material research

Hongke solutions Onyx The system provides a non-destructive 、 Contactless 、 Fast and high-resolution detection method , Block materials can be drawn 、 Film and 2D material （ Like graphene ） Electrical characteristic diagram of . As a non-contact method without sample preparation 、 Non destructive method , Terahertz time domain spectroscopy can be used for the same research sample （THz-TDS） Conduct multiple analyses , There is no need to modify it . The electrical characteristic diagram of the whole sample area can be obtained instead of a single point , Defects can be identified , Uniformity, etc .

Several scientific articles published in peer-reviewed journals with high impact factors have been used  Onyx  Data obtained by the system . The following example is related to  Graphenea  Jointly released .

In the article “Mapping the conductivity of graphene with Electrical Resistance Tomography” 【“ The conductivity of graphene is plotted by electrical resistance tomography ”】（Cultrera wait forsomeone , Scientific report ,2019,9：10655） in , Use contact method （ Electrical resistance tomography （ERC） and van der Pauw measurement ） And non-contact THz-TDS Onyx The resistance measurement results of large area graphene samples were obtained .

The figure above compares the use of ERC and Onyx（TDS） To obtain the 10×10 mm2 Regional chemical vapor deposition （CVD） Graphene conductivity diagram .Onyx Image inclusion 100×100 Pixel , Each pixel corresponds to a measured value , It also allows the identification of heterogeneity along the surface of graphene samples in a non-destructive and non-contact manner , Ensure the integrity of the sample after measurement .

In the article “Towards standardisation of contact and contactless electrical measurements of CVD graphene at the macro-, micro- and nano-scale” 【“ At the macro level , On micro and nano scales CVD Standardization of contact and non-contact electrical measurement of graphene ”】（Melios wait forsomeone , Scientific report ,2020,10：3223）, A comprehensive method for measuring the electrical properties of graphene from nano to macro scale is presented .

Electrical characterization is achieved by using a combination of various technologies , Including magnetic transmission in Vanderbilt geometry , Use Onyx Terahertz time domain spectrum rendering of the system （ Two resistivity charts are shown above ） And calibrated Kelvin probe force microscope . The results show good consistency between different technologies .

Besides , stay GRACE EMPIR/EURAMET Two good practice guides on the electrical characterization of graphene have also been released in the project ：

“Good Practice Guide on the electrical characterization of graphene using non-contact and high-throughput methods” 【“ Good practice guide for electrochemical characterization of graphene using non-contact and high-throughput methods ”】（2020 year , from A. Fabricius,A. Waiting to be edited ,ISBN：978-88-945324-2-5）.

“Good Practice Guide on the electrical characterisation of graphene using contact methods” 【“ Good practice guide for electrochemical characterization of graphene using contact methods ”】（2020 year , from A. Fabricius Waiting to be edited ,ISBN：978-88-945324-0-1）.

These two guidelines are designed to meet the need for standardized electrical measurements under highly controlled environmental conditions .

If you are right about Siphonaceae Onyx Terahertz nondestructive characterization platform Interested in , Want to know the quotation 、 model 、 Parameter information , Welcome to call or leave a message , We will serve you wholeheartedly ！