Enhanced terahertz conductivity in ultra-thin gold film deposited onto (3-mercaptopropyl) trimethoxysilane (MPTMS)-coated Si substrates

Abstract Various material properties change considerably when material is thinned down to nanometer thicknesses. Accordingly, researchers have been trying to obtain homogeneous thin films with nanometer thickness but depositing homogeneous few nanometers thick gold film is challenging as it tends to form islands rather than homogenous film. Recently, studies have revealed that treating the substrate with an organic buffer, (3-mercaptopropyl) trimethoxysilane (MPTMS) enables deposition of ultra-thin gold film having thickness as low as 5 nm. Different aspects of MPTMS treatment for ultra-thin gold films like its effect on the structure and optical properties at visible wavelengths have been investigated. However, the effect of the MPTMS treatment on electrical conductivity of ultra-thin gold film at terahertz frequency remains unexplored. Here, we measure the complex conductivity of nanometer-thick gold films deposited onto an MPTMS-coated silicon substrate using terahertz time-domain spectroscopy. Following the MPTMS treatment of the substrate, the conductivity of the films was found to increase compared to those deposited onto uncoated substrate for gold films having the thickness less than 11 nm. We observed 5-fold enhancement in the conductivity for a 7 nm-thick gold film. We also demonstrate the fabrication of nanoslot-antenna arrays in 8.2-nm-thick gold films. The nanoslot-antenna with MPTMS coating has resonance at around 0.5 THz with an electric field enhancement of 44, whereas the nanoslot-antenna without MPTMS coating does not show resonant properties. Our results demonstrate that gold films deposited onto MPTMS-coated silicon substrates are promising advanced materials for fabricating ultra-thin terahertz plasmonic devices.

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LOCALIZED SURFACE PLASMON OF THIN GOLD FILM WITH PERIODIC ARRAYS OF NANOHOLES

Modern Physics Letters B ◽

10.1142/s0217984909017960 ◽

2009 ◽

Vol 23 (02) ◽

pp. 147-153 ◽

Cited By ~ 1

Author(s):

ZONG-SUO ZHANG ◽

XIONG-RUI SU ◽

JIAN-BO LI ◽

ZHONG-HUA HAO ◽

LI ZHOU

Keyword(s):

Surface Plasmon ◽

Gold Film ◽

Dipole Approximation ◽

Resonance Peak ◽

Localized Surface Plasmon ◽

Gold Films ◽

Thin Gold Film ◽

Periodic Arrays ◽

Edge Separation ◽

Plasmon Polaritons

The localized surface plasmon (LSP) resonances properties of periodic arrays of nanoholes in thin gold films are investigated by using the method of discrete dipole approximation (DDA). The surface plasmon polaritons (SPPs) play important roles in amplification or suppression of the LSP resonances in the film. The LSP-SPP coupling is affirmed based on the extinction spectra calculated by the DDA. The intensity of the LSP resonances can be controlled through changing the edge-to-edge separation distances between nanoholes, the number and the diameter of the nanoholes. The calculations also indicate that the LSP resonance peak decreases with increasing the thickness of the gold film.

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Electronic Thermal Conduction in Thin Gold Films

Heat Transfer: Volume 3 ◽

10.1115/ht2003-47172 ◽

2003 ◽

Cited By ~ 6

Author(s):

Basil T. Wong ◽

M. Pinar Mengu¨c¸

Keyword(s):

Heat Transfer ◽

Monte Carlo ◽

Thermal Conduction ◽

Gold Film ◽

Boltzmann Transport Equation ◽

Gold Films ◽

Temperature Profiles ◽

Boltzmann Transport ◽

Fourier Law ◽

Thin Gold Film

In this work, electronic thermal conduction in thin gold film is modeled via the Boltzmann Transport Equation (BTE). The BTE is solved using a Monte Carlo Method (MCM). Temperature profiles for various film thicknesses are computed. Results show that the electronic thermal transport in gold is still diffusion-like at film thicknesses as small as 100 nm, implying that the Fourier law of conduction can be applied at this scale to predict the steady-state thermal heat transfer without comprising the physics. However, the Fourier law does not predict the temperature profiles accurately if the film thickness is reduced to 10 nm or below.

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Nano-Folded Gold Electrocatalysts Enhance the Selectivity of Carbon Dioxide Reduction

10.26434/chemrxiv.8296193 ◽

2019 ◽

Author(s):

Kam Sang Kwok ◽

Yuxuan Wang ◽

Michael Cao ◽

Hao Shen ◽

Weinan Xu ◽

...

Keyword(s):

Carbon Dioxide ◽

Mass Transport ◽

Gold Film ◽

X Ray Diffraction ◽

Thin Gold Film ◽

Faradaic Efficiency ◽

X Ray ◽

Transmission Electron ◽

Carbon Monoxide Formation ◽

Catalytic Interfaces

<p>The local structure and geometry of catalytic interfaces can influence the selectivity of chemical reactions. Here, using a pre-strained polymer, we uniaxially compress a thin gold film to form a nano-folded catalyst. We observe two kinds of folds and can tune the ratio of loose to tight folds by varying the extent of pre-strain in the polymer. We characterize the nano-folded catalysts using x-ray diffraction, scanning, and transmission electron microscopy. We observe grain reorientation and coarsening in the nano-folded gold catalysts. Electroreduction of carbon dioxide with these nano-folded catalysts reveals an enhancement of Faradaic efficiency for carbon monoxide formation by a factor of about four. This result suggests that electrolyte mass transport limitations and an increase of the local pH in the tight folds of the catalyst outweigh the effects of alterations in grain characteristics. Together, our studies demonstrate that nano-folded geometries can significantly alter grain characteristics, mass transport, and catalytic selectivity. </p>

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Increased transmission of a thin gold film by adsorbed layers of dye molecules

Applied Physics Letters ◽

10.1063/1.1480471 ◽

2002 ◽

Vol 80 (20) ◽

pp. 3715-3717 ◽

Cited By ~ 10

Author(s):

Ulrich C. Fischer ◽

Eugene Bortchagovsky ◽

Jörg Heimel ◽

René T. Hanke

Keyword(s):

Gold Film ◽

Dye Molecules ◽

Thin Gold Film ◽

Adsorbed Layers

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Femtosecond pulsed laser ablation of thin gold film

Optics & Laser Technology ◽

10.1016/s0030-3992(01)00110-4 ◽

2002 ◽

Vol 34 (3) ◽

pp. 199-202 ◽

Cited By ~ 21

Author(s):

K. Venkatakrishnan ◽

B. Tan ◽

B.K.A. Ngoi

Keyword(s):

Laser Ablation ◽

Gold Film ◽

Pulsed Laser ◽

Pulsed Laser Ablation ◽

Thin Gold Film ◽

Femtosecond Pulsed Laser

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Model of atomic hydrogen adsorption on thin gold film surface

Vacuum ◽

10.1016/0042-207x(94)90194-5 ◽

1994 ◽

Vol 45 (2-3) ◽

pp. 299-301 ◽

Cited By ~ 19

Author(s):

L. Stobiński ◽

R. Duś

Keyword(s):

Atomic Hydrogen ◽

Hydrogen Adsorption ◽

Gold Film ◽

Film Surface ◽

Thin Gold Film

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Tuning the resonance of silver nanoprisms by plasmonic hybridization with a thin gold film

2011 11th IEEE International Conference on Nanotechnology ◽

10.1109/nano.2011.6144496 ◽

2011 ◽

Author(s):

Ghazal Hajisalem ◽

Yuanjie Pang ◽

Reuven Gordon

Keyword(s):

Gold Film ◽

Thin Gold Film ◽

Silver Nanoprisms

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Non-Fourier heat conduction in a thin gold film heated by an ultra-fast-laser

Science China Technological Sciences ◽

10.1007/s11431-015-5767-6 ◽

2015 ◽

Vol 58 (4) ◽

pp. 638-649 ◽

Cited By ~ 6

Author(s):

YuDong Mao ◽

MingTian Xu

Keyword(s):

Heat Conduction ◽

Gold Film ◽

Thin Gold Film ◽

Fourier Heat Conduction

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Study the Heat Transfer Process From Electron-Phonon Nonequilibrium in Thin Gold Film to Glass Substrate Through Transient Thermoreflectance Measurements

ASME 2010 8th International Conference on Nanochannels, Microchannels, and Minichannels: Parts A and B ◽

10.1115/fedsm-icnmm2010-30364 ◽

2010 ◽

Author(s):

Weigang Ma ◽

Haidong Wang ◽

Xing Zhang ◽

Wei Wang

Keyword(s):

Heat Transfer ◽

Transfer Process ◽

Borosilicate Glass ◽

Glass Substrate ◽

Physical Vapor Deposition ◽

Gold Film ◽

Coupling Factor ◽

Heat Transfer Process ◽

Thin Gold Film ◽

Open Question

How the energy transfers during electron-phonon nonequilibrium in thin metal films is still an open question, and how to measure the intrinsic thermal transport properties of the material under the covering layer is another challenge. In this paper, the heat transfer process from electron-phonon nonequilibrium in thin gold film to borosilicate glass substrate has been studied by resorting to different segments of the transient thermoreflectance signal, which is obtained from the rear-pump front-probe transient thermoreflectance technique. The gold film, which has a thickness of 23.1 nm, is deposited on the borosilicate glass substrate using using a physical vapor deposition (PVD) approach. Within the framework of the two-temperature model (TTM), the electron-phonon (e-ph) coupling factors of the gold film, which reflect the strength of heat flow from hot electrons to cold phonons, are derived from the signal taken after the first several picoseconds with different pump fluences, and the measured value is (1.95–2.05)×1016 W m−3 K−1. The electron-phonon coupling factor does not significantly change in response to the pump pulse fluence variation and exhibits little change compared to the bulk gold value 2.4×1016 W m−3 K−1. Furthermore, the thermal conductivity of the glass substrate is obtained through the thermoreflectance signal between 20 to 140 picoseconds and the value is W m−1 K−1.

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