Article

1998 ◽  
Vol 76 (11) ◽  
pp. 1766-1778
Author(s):  
Chi Ming Yam ◽  
Adam Dickie ◽  
Aramice Malkhasian ◽  
Ashok K Kakkar ◽  
M A Whitehead
Keyword(s):  
Thin Films ◽  
Molecular Mechanics ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Molecular Orbitals ◽  
Base Hydrolysis ◽  
Crystal Silicon ◽  
Topochemical Polymerization ◽  
Modeling Studies ◽  
Rigid Rod

The hydrolysis of surface-bound basic tin-amide moieties with acidic protons of alkynyl chromophores leads to molecular self-assembly of a variety of rigid-rod alkynes on inorganic oxide surfaces such as glass, quartz, and single crystal silicon. Characterization of these newly developed thin films was achieved by contact-angle goniometry, FTIR-ATR, ellipsometry, and X-ray photoelectron spectroscopy, which indicate that these thin films are densely packed. Comparative molecular mechanics modeling studies on unbound and chemisorbed -Sn-Ctriple bondC-H monomer, dimer, trimer, and a 12 × 12 (144 molecule) model substrate, suggest that surface anchoring of Sn-alkynyl units is essential for highly ordered thin-film structures that can effect topochemical polymerization. Preliminary MO calculations on a 4 × 4 model show conjugated molecular orbitals through the system.Key words: molecular self-assembly, rigid-rod alkynes, acid-base hydrolysis, tin-alkynyl thin films, molecular mechanics modeling studies, topochemical polymerization, molecular orbitals.

X-ray Photoelectron Spectroscopy Study of the Deposition of TiO2 Thin Films on Self-assembly Monolayer

1998 ◽  
Vol 14 (01) ◽  
pp. 57-62
Author(s):  
Xiao Zhong-Dang ◽  
◽  
Huang Dan ◽  
Gu Jian-Hua ◽  
Lu Zu-Hong
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Spectroscopy Study ◽  
X Ray

The deposition of TiO 2 thin films on self-assembly monolayers studied by X-ray photoelectron spectroscopy

1998 ◽  
Vol 125 (1) ◽  
pp. 85-92 ◽  
Author(s):  
Zhongdang Xiao ◽  
Jianhua Gu ◽  
Dan Huang ◽  
Zuhong Lu ◽  
Yu Wei
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
X Ray

MOLECULAR SELF-ASSEMBLY OF SULFONATED POLYANILINE THIN FILMS

2001 ◽  
Vol 08 (05) ◽  
pp. 491-496 ◽  
Author(s):  
W. S. SIM ◽  
F. Y. GOH
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Structural Integrity ◽  
Layer Growth ◽  
Polymer Chains ◽  
Layer By Layer ◽  
Vis Spectroscopy ◽  
Polyelectrolyte Solutions ◽  
Sulfonated Polyaniline

Multilayer polymer thin films with well-defined molecular architectures have been fabricated by an electrostatic self-assembly process involving sequential exposure of glass substrates to polyelectrolyte solutions of sulfonated polyaniline and hexadimethrine bromide. Ultraviolet-Visible (UV-Vis) Spectroscopy indicates layer-by-layer growth of alternating monolayers of oppositely charged polymer chains whose structural integrity is verified by X-ray Photoelectron Spectroscopy (XPS). The surface roughness is measured to be ~3 nm by Atomic Force Microscopy (AFM). The potential applications of these films in optoelectronic devices are discussed.

The Effects of the Self-Assembly Time on the Preparation of Lanthanum-Based Thin Films on Sulfonated 3-Mercaptopropyl Trimethoxysilane

2012 ◽  
Vol 164 ◽  
pp. 284-288
Author(s):  
Tao Bai ◽  
Xian Hua Cheng
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Self Assembled Monolayer ◽  
X Ray ◽  
Assembly Time ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements

Lanthanum-based thin films are deposited on the oxidized 3-mercaptopropyl trimethoxysilane self-assembled monolayer (MPTS-SAM) based on the chemisorption of the sulfonic group. The surface energy, chemical composition, phase transformation and surface morphology of the films are analyzed by using contact angle measurements, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The experimental results indicate that the lanthanum-based thin films are absorbed on oxidized MPTS-SAM and lanthanum element with different oxidation states exists in the thin films deposited on the surface of self-assembly monolayers. The content of lanthanum on the oxidized MPTS-SAM increases with the extension of the assembly time and the rare earth reached saturation when the time was 6h.

scholarly journals Preparation and Investigation of the Microtribological Properties of Graphene Oxide and Graphene Films via Electrostatic Layer-by-Layer Self-Assembly

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Yongshou Hu ◽  
Haibing Ma ◽  
Wei Liu ◽  
Qianqian Lin ◽  
Bin Liu
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Adhesion Force ◽  
Strong Dependence ◽  
Layer By Layer ◽  
Crystal Silicon ◽  
X Ray ◽  
Graphene Films ◽  
Self Assembled

Graphene oxide (GO) films with controlled layers, deposited on single-crystal silicon substrates, were prepared by electrostatic self-assembly of negatively charged GO sheets. Afterward, graphene films were prepared by liquid-phase reduction of as-prepared GO films using hydrazine hydrate. The microstructures and microtribological properties of the samples were studied using X-ray photoelectron spectroscopy, Raman spectroscopy, X-ray diffraction, UV-visabsorption spectroscopy, water contact angle measurement, and atomic force microscopy. It is found that, whether GO films or graphene films, the adhesion force and the coefficients of friction both show strong dependence on the number of self-assembled layers, which both allow a downward trend as the number of self-assembled layers increases due to the interlayer sliding and the puckering effect when the tip slipped across the top surface of the films. Moreover, in comparison with the GO films with the same self-assembled layers, the graphene films possess lower adhesion force and coefficient of friction attributed to the difference of surface functional groups.

Photoelectron Spectroscopy Measurements of the Valence Band Structures of C60 Thin Films on Single Crystal Silicon and Polycrystalline Copper

2002 ◽  
Vol 734 ◽  
Author(s):  
B. Ha ◽  
J. H. Rhee ◽  
Y. Li ◽  
D. Singh ◽  
S. C. Sharma
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Valence Band ◽  
Photoelectron Spectroscopy ◽  
Thermal Evaporation ◽  
High Vacuum ◽  
Single Crystal Silicon ◽  
Polycrystalline Copper ◽  
Band Structures ◽  
Crystal Silicon

ABSTRACTWe have used photoelectron spectroscopy to study possible modifications in the electronic valence band structures of thin films of C60 due to their deposition on single crystal silicon and polycrystalline copper. The C60 thin films were deposited by thermal evaporation under high vacuum and further characterized by using Raman spectroscopy. We observe significant differences in the valence band structures of C60 thin films deposited on these substrates and attribute them to interactions at the interface.

A New Route to Prepare Hard and Anti-Scratching Coatings at Room Temperature

1999 ◽  
Vol 576 ◽  
Author(s):  
Yanjing Liu ◽  
Richard O. Claus ◽  
Aprillya Rosidian ◽  
Tingying Zeng
Keyword(s):  
Thin Films ◽  
Self Assembly ◽  
Room Temperature ◽  
Single Crystal Silicon ◽  
Crystal Silicon ◽  
Linear Behavior ◽  
Vis Spectroscopy ◽  
Novel Method ◽  
Quartz Substrates ◽  
Cationic Polyelectrolytes

ABSTRACTNanocomposites of transparent, multilayer structures of different thin-films have been fabricated on single crystal silicon and quartz substrates by the new deposition technique called electrostatic self-assembly (ESA) method. The method is based on the alternating adsorption of anionic and cationic polyelectrolytes in the aqueous forms. The films were then characterized by UV/Vis spectroscopy, ellipsometry, and nano-indenter. A linear behavior of both optical absorption and film thickness as the number of bilayers increases was observed, which indicated the formation of homogeneous and uniform thin-films on both substrates. The study also observed that the films prepared by this novel method have some improved mechanical properties.

Phase configuration, nanostructure, and mechanical behaviors in Ti-B-C-N thin films

2009 ◽  
Vol 24 (8) ◽  
pp. 2520-2527 ◽  
Author(s):  
Yonghao Lu ◽  
Junping Wang ◽  
Yaogen Shen ◽  
Dongbai Sun
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Solid Solution Hardening ◽  
Mechanical Behaviors ◽  
Additional Increase ◽  
N Content ◽  
X Ray ◽  
Nanocomposite Thin Films ◽  
The Cost ◽  
Nano Grains

A series of Ti-B-C-N thin films were deposited on Si (100) at 500 °C by incorporation of different amounts of N into Ti-B-C using reactive unbalanced dc magnetron sputtering in an Ar-N2 gas mixture. The effect of N content on phase configuration, nanostructure evolution, and mechanical behaviors was studied by x-ray diffraction, x-ray photoelectron spectroscopy, Raman spectroscopy, high-resolution transmission electron microscopy, and microindentation. It was found that the pure Ti-B-C was two-phased quasi-amorphous thin films comprising TiCx and TiB2. Incorporation of a small amount of N not only dissolved into TiCx but also promoted growth of TiCx nano-grains. As a result, nanocomposite thin films of nanocrystalline (nc-) TiCx(Ny) (x + y < 1) embedded into amorphous (a-) TiB2 were observed until nitrogen fully filled all carbon vacancy lattice (at that time x + y = 1). Additional increase of N content promoted formation of a-BN at the cost of TiB2, which produced nanocomposite thin films of nc-Ti(Cx,N1-x) embedded into a-(TiB2, BN). Formation of BN also decreased nanocrystalline size. Both microhardness and elastic modulus values were increased with an increase of N content and got their maximums at nanocomposite thin films consisting of nc-Ti(Cx,N1-x) and a-TiB2. Both values were decreased after formation of BN. Residual compressive stress value was successively decreased with an increase of N content. Enhancement of hardness was attributed to formation of nanocomposite structure and solid solution hardening.

scholarly journals Optical Constant and Conformality Analysis of SiO2 Thin Films Deposited on Linear Array Microstructure Substrate by PECVD

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 510
Author(s):  
Yongqiang Pan ◽  
Huan Liu ◽  
Zhuoman Wang ◽  
Jinmei Jia ◽  
Jijie Zhao
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Deposition Rate ◽  
Optical Constant ◽  
Photoelectron Spectroscopy ◽  
Linear Array ◽  
Chemical Vapor ◽  
Rf Plasma ◽  
X Ray ◽  
Sio2 Thin Film

SiO2 thin films are deposited by radio frequency (RF) plasma-enhanced chemical vapor deposition (PECVD) technique using SiH4 and N2O as precursor gases. The stoichiometry of SiO2 thin films is determined by the X-ray photoelectron spectroscopy (XPS), and the optical constant n and k are obtained by using variable angle spectroscopic ellipsometer (VASE) in the spectral range 380–1600 nm. The refractive index and extinction coefficient of the deposited SiO2 thin films at 500 nm are 1.464 and 0.0069, respectively. The deposition rate of SiO2 thin films is controlled by changing the reaction pressure. The effects of deposition rate, film thickness, and microstructure size on the conformality of SiO2 thin films are studied. The conformality of SiO2 thin films increases from 0.68 to 0.91, with the increase of deposition rate of the SiO2 thin film from 20.84 to 41.92 nm/min. The conformality of SiO2 thin films decreases with the increase of film thickness, and the higher the step height, the smaller the conformality of SiO2 thin films.

scholarly journals A novel and potentially scalable CVD-based route towards SnO2:Mo thin films as transparent conducting oxides

2021 ◽  
Author(s):  
Tianlei Ma ◽  
Marek Nikiel ◽  
Andrew G. Thomas ◽  
Mohamed Missous ◽  
David J. Lewis
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Mixed Valence ◽  
Chemical Vapour ◽  
X Ray Diffraction ◽  
X Ray ◽  
Conducting Oxides ◽  
Valence States ◽  
3 Omega ◽  
First Time

AbstractIn this report, we prepared transparent and conducting undoped and molybdenum-doped tin oxide (Mo–SnO2) thin films by aerosol-assisted chemical vapour deposition (AACVD). The relationship between the precursor concentration in the feed and in the resulting films was studied by energy-dispersive X-ray spectroscopy, suggesting that the efficiency of doping is quantitative and that this method could potentially impart exquisite control over dopant levels. All SnO2 films were in tetragonal structure as confirmed by powder X-ray diffraction measurements. X-ray photoelectron spectroscopy characterisation indicated for the first time that Mo ions were in mixed valence states of Mo(VI) and Mo(V) on the surface. Incorporation of Mo6+ resulted in the lowest resistivity of $$7.3 \times 10^{{ - 3}} \Omega \,{\text{cm}}$$ 7.3 × 10 - 3 Ω cm , compared to pure SnO2 films with resistivities of $$4.3\left( 0 \right) \times 10^{{ - 2}} \Omega \,{\text{cm}}$$ 4.3 0 × 10 - 2 Ω cm . Meanwhile, a high transmittance of 83% in the visible light range was also acquired. This work presents a comprehensive investigation into impact of Mo doping on SnO2 films synthesised by AACVD for the first time and establishes the potential for scalable deposition of SnO2:Mo thin films in TCO manufacturing. Graphical abstract

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