Dielectric constant measurement using atomic force microscopy of dielectric films: a system theory approach

Cruz-Valeriano, E.; Guzmán, David Saeteros; Escamilla-Díaz, T.; Gutierrez-Peralta, A.; Dávila, Susana Meraz; Torres-Ochoa, J.A.; Gervacio-Arciniega, J. J.; Murillo-Bracamontes, E. A.; Enriquez-Flores, C. I.; Ramı́rez-Bon, R.; Palmerín, Joel Moreno; Yáñez‐Limón, J. M.

doi:10.1007/s00339-018-2093-4

Cited by 5 publications

(3 citation statements)

References 16 publications

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“…The surface potential ( V s ) was calculated from the CPD of Figure S8. The capacitances for metal and dielectric samples are calculated by using the two equations , where z , R , h and θ are the distance between tip and sample, the radius of the tip, the thickness of the dielectrics, and the cone angle of the tip apex, respectively. Combining eqs , and yields the capacitive force exerted on the tip as follows for metal for dielectric.…”

Section: Resultsmentioning

confidence: 99%

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Thickness-Insensitive Properties of α-MoO₃ Nanosheets by Weak Interlayer Coupling

et al. 2019

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van der Waals (vdW) materials have shown unique electrical and optical properties depending on the thickness due to strong interlayer interaction and symmetry breaking at the monolayer level. In contrast, the study of electrical and tribological properties and their thickness-insensitivity of van der Waals oxides are lacking due to difficulties in the fabrication of high quality two-dimensional oxides and the investigation of nanoscale properties. Here we investigated various tribological and electrical properties, such as, friction, adhesion, work function, tunnel current, and dielectric constant, of the single-crystal α-MoO3 nanosheets epitaxially grown on graphite by using atomic force microscopy. The friction of atomically smooth MoO3 is rapidly saturated within a few layers. The thickness insensitivity of friction is due to very weak mechanical interlayer interaction. Similarly, work function (4.73 eV for 2 layers (hereafter denoted as L)) and dielectric constant (6 for 2L and 10.5–11 for >3L) of MoO3 in MoO3 showed thickness insensitivity due to weak interlayer coupling. Tunnel current measurements by conductive atomic force microscopy showed that even 2L MoO3 of 1.4 nm is resistant to tunneling with a high dielectric strength of 14 MV/cm. The thickness-indifferent electrical properties of high dielectric constant and tunnel resistance by weak interlayer coupling and high crystallinity show a promise in the use of MoO3 nanosheets for nanodevice applications.

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Section: Resultsmentioning

confidence: 99%

“…The surface potential (V s ) was calculated from the CPD of Figure S8. The capacitances for metal and dielectric samples are calculated by using the two equations 44,45…”

mentioning

confidence: 99%

Thickness-Insensitive Properties of α-MoO₃ Nanosheets by Weak Interlayer Coupling

et al. 2019

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“…The 2D GaO X bilayer exhibited dielectric breakdown voltages of ±6 V. The dielectric constant (6.5) of the 2D GaO X bilayer was evaluated via F–D spectroscopy and KPFM (Figure S7). The dielectric constant of a thin insulating film can be estimated by using the equation − F false( z false) = F 0 − 2 π ε 0 R 2 false( 1 − sin .25em θ false) true( z + h ε normalr true) true( z + h ε normalr + R ( 1 − sin θ ) true) false( V tip − V normals false) 2 where F ( z ) is the capacitive force to the tip apex, F 0 is the force against the tip, ε 0 is the vacuum permittivity, R is the radius of the tip apex, θ is the cone angle of the tip apex, z is the distance between the tip and the sample, h is the thickness of the insulating film, ε r is the dielectric constant of the insulating film, V tip is the tip bias voltage, and V s is the surface potential. KPFM was performed on 2D GaO X bilayer and Au electrode to obtain the contact potential difference between the tip and the 2D GaO X bilayer (Figure S7a–c), which was used to determine the V s .…”

Section: Resultsmentioning

confidence: 99%

2D Amorphous GaO_X Gate Dielectric for β-Ga₂O₃ Field-Effect Transistors

Moon

Lee

Park

et al. 2023

ACS Appl. Mater. Interfaces

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Appropriate gate dielectrics must be identified to fabricate metal–insulator–semiconductor field-effect transistors (MISFETs); however, this has been challenging for compound semiconductors owing to the absence of high-quality native oxides. This study uses the liquid-gallium squeezing technique to fabricate 2D amorphous gallium oxide (GaOX) with a high dielectric constant, where its thickness is precisely controlled at the atomic scale (monolayer, ∼4.5 nm; bilayer, ∼8.5 nm). Beta-phase gallium oxide (β-Ga2O3) with an ultrawide energy bandgap (4.5–4.9 eV) has emerged as a next-generation power semiconductor material and is presented here as the channel material. The 2D amorphous GaOX dielectric is combined with a β-Ga2O3 conducting nanolayer, and the resulting β-Ga2O3 MISFET is stable up to 250 °C. The 2D amorphous GaOX is oxygen-deficient, and a high-quality interface with excellent uniformity and scalability forms between the 2D amorphous GaOX and β-Ga2O3. The fabricated MISFET exhibits a wide gate-voltage swing of approximately +5 V, a high current on/off ratio, moderate field-effect carrier mobility, and a decent three-terminal breakdown voltage (∼138 V). The carrier transport of the Ni/GaOX/β-Ga2O3 metal–insulator–semiconductor (MIS) structure displays a combination of Schottky emission and Fowler–Nordheim (F–N) tunneling in the high-gate-bias region at 25 °C, whereas at elevated temperatures it shows Schottky emission and F–N tunneling in the low- and high-gate-bias regions, respectively. This study demonstrates that a 2D GaOX gate dielectric layer can be produced and incorporated into an active channel layer to form an MIS structure at room temperature (∼25 °C), which enables the facile fabrication of MISFET devices.

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Molecular Mechanisms and Enhancement of Piezoelectricity in the M13 Virus

Kim,

Lee

2024

Adv Funct Materials

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Understanding the structure and function of bioelectric materials is challenging due to the complex nature of biomaterials and a lack of appropriate tools. The precisely defined structures and genetic tunability of viruses provide an excellent model system to investigate bioelectrical behavior in biomaterials. This study presents the molecular mechanisms of piezoelectricity in the M13 bacteriophage (phage) under various mechanical stresses for bio‐piezoelectric generation. A computational approach is used to calculate the piezoelectric tensors of the M13 phage and quantify its direction‐dependent dipole moments. By computationally designing negatively charged residues on the phage surface, the surface charge density is enhanced to 16.7 µC cm−2. Using genetic engineering, phages are experimentally designed with different charges and tail structures to create model phage nanostructures, including individual phages, vertically standing phage films, and horizontally aligned phage films. Their vertical, horizontal, and shear‐mode piezoelectric properties are then measured using scanning probe microscopy techniques. The resulting phage‐based piezoelectric energy generators exhibit an effective piezoelectric coefficient of 15.4 pm V−1 and a power density of 4.2 µW cm−2. This phage‐based bioengineering approach provides a versatile platform for investigating fundamental mechanisms of bioelectricity and designing bioelectric materials for applications in energy harvesting, biomemory, and biosensors.

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Dielectric constant measurement using atomic force microscopy of dielectric films: a system theory approach

Cited by 5 publications

References 16 publications

Thickness-Insensitive Properties of α-MoO₃ Nanosheets by Weak Interlayer Coupling

Thickness-Insensitive Properties of α-MoO₃ Nanosheets by Weak Interlayer Coupling

2D Amorphous GaO_X Gate Dielectric for β-Ga₂O₃ Field-Effect Transistors

Molecular Mechanisms and Enhancement of Piezoelectricity in the M13 Virus

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Dielectric constant measurement using atomic force microscopy of dielectric films: a system theory approach

Cited by 5 publications

References 16 publications

Thickness-Insensitive Properties of α-MoO3 Nanosheets by Weak Interlayer Coupling

Thickness-Insensitive Properties of α-MoO3 Nanosheets by Weak Interlayer Coupling

2D Amorphous GaOX Gate Dielectric for β-Ga2O3 Field-Effect Transistors

Molecular Mechanisms and Enhancement of Piezoelectricity in the M13 Virus

Contact Info

Product

Resources

About

Thickness-Insensitive Properties of α-MoO₃ Nanosheets by Weak Interlayer Coupling

Thickness-Insensitive Properties of α-MoO₃ Nanosheets by Weak Interlayer Coupling

2D Amorphous GaO_X Gate Dielectric for β-Ga₂O₃ Field-Effect Transistors