X-ray photoelectron spectroscopy investigation of oxidation states in molybdenum thin films for Cu(InGa)Se2 applications

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.

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

Coatings ◽

10.3390/coatings11050510 ◽

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.

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

Journal of Materials Science ◽

10.1007/s10853-021-06269-3 ◽

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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X-ray Photoelectron Spectroscopy Analysis of Chitosan–Graphene Oxide-Based Composite Thin Films for Potential Optical Sensing Applications

Polymers ◽

10.3390/polym13030478 ◽

2021 ◽

Vol 13 (3) ◽

pp. 478

Author(s):

Wan Mohd Ebtisyam Mustaqim Mohd Daniyal ◽

Yap Wing Fen ◽

Silvan Saleviter ◽

Narong Chanlek ◽

Hideki Nakajima ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Graphene Oxide ◽

Photoelectron Spectroscopy ◽

Functional Group ◽

Optical Sensing ◽

Composite Thin Films ◽

Cobalt Ions ◽

X Ray ◽

Sensing Applications

In this study, X-ray photoelectron spectroscopy (XPS) was used to study chitosan–graphene oxide (chitosan–GO) incorporated with 4-(2-pyridylazo)resorcinol (PAR) and cadmium sulfide quantum dot (CdS QD) composite thin films for the potential optical sensing of cobalt ions (Co2+). From the XPS results, it was confirmed that carbon, oxygen, and nitrogen elements existed on the PAR–chitosan–GO thin film, while for CdS QD–chitosan–GO, the existence of carbon, oxygen, cadmium, nitrogen, and sulfur were confirmed. Further deconvolution of each element using the Gaussian–Lorentzian curve fitting program revealed the sub-peak component of each element and hence the corresponding functional group was identified. Next, investigation using surface plasmon resonance (SPR) optical sensor proved that both chitosan–GO-based thin films were able to detect Co2+ as low as 0.01 ppm for both composite thin films, while the PAR had the higher binding affinity. The interaction of the Co2+ with the thin films was characterized again using XPS to confirm the functional group involved during the reaction. The XPS results proved that primary amino in the PAR–chitosan–GO thin film contributed more important role for the reaction with Co2+, as in agreement with the SPR results.

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The Growth and Characterization of Germanium-Carbon Alloy Thin Films

MRS Proceedings ◽

10.1557/proc-270-91 ◽

1992 ◽

Vol 270 ◽

Author(s):

Haojie Yuan ◽

R. Stanley Williams

Keyword(s):

Thin Films ◽

Photoelectron Spectroscopy ◽

Vacuum Chamber ◽

Optical Band Gap ◽

High Vacuum ◽

Optical Absorption Spectroscopy ◽

Alloy Thin Film ◽

New Materials ◽

X Ray

ABSTRACTThin films of pure germanium-carbon alloys (GexC1−x with x ≈ 0.0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0) have been grown on Si(100) and A12O3 (0001) substrates by pulsed laser ablation in a high vacuum chamber. The films were analyzed by x-ray θ-2θ diffraction (XRD), x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), conductivity measurements and optical absorption spectroscopy. The analyses of these new materials showed that films of all compositions were amorphous, free of contamination and uniform in composition. By changing the film composition, the optical band gap of these semiconducting films was varied from 0.00eV to 0.85eV for x = 0.0 to 1.0 respectively. According to the AES results, the carbon atoms in the Ge-C alloy thin film samples has a bonding configuration that is a mixture of sp2 and sp3 hybridizations.

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Reactive Dual Magnetron Sputtering: A Fast Method for Preparing Stoichiometric Microcrystalline ZnWO4 Thin Films

Surfaces ◽

10.3390/surfaces4020013 ◽

2021 ◽

Vol 4 (2) ◽

pp. 106-114

Author(s):

Yannick Hermans ◽

Faraz Mehmood ◽

Kerstin Lakus-Wollny ◽

Jan P. Hofmann ◽

Thomas Mayer ◽

...

Keyword(s):

Thin Films ◽

Magnetron Sputtering ◽

Photoelectron Spectroscopy ◽

Fast Method ◽

X Ray Diffraction ◽

X Ray ◽

Glass Substrates ◽

Post Annealing ◽

Rf Signal ◽

First Time

Thin films of ZnWO4, a promising photocatalytic and scintillator material, were deposited for the first time using a reactive dual magnetron sputtering procedure. A ZnO target was operated using an RF signal, and a W target was operated using a DC signal. The power on the ZnO target was changed so that it would match the sputtering rate of the W target operated at 25 W. The effects of the process parameters were characterized using optical spectroscopy, X-ray diffraction, and scanning electron microscopy, including energy dispersive X-ray spectroscopy as well as X-ray photoelectron spectroscopy. It was found that stoichiometric microcrystalline ZnWO4 thin films could be obtained, by operating the ZnO target during the sputtering procedure at a power of 55 W and by post-annealing the resulting thin films for at least 10 h at 600 °C. As FTO coated glass substrates were used, annealing led as well to the incorporation of Na, resulting in n+ doped ZnWO4 thin films.

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Effects of Perpendicular Magnetic Field Annealing on the Structural and Magnetic Properties of [Co/Ni]2/PtMn Thin Films

Magnetochemistry ◽

10.3390/magnetochemistry7030038 ◽

2021 ◽

Vol 7 (3) ◽

pp. 38

Author(s):

Roshni Yadav ◽

Chun-Hsien Wu ◽

I-Fen Huang ◽

Xu Li ◽

Te-Ho Wu ◽

...

Keyword(s):

Magnetic Field ◽

Thin Films ◽

Magnetic Properties ◽

Photoelectron Spectroscopy ◽

Perpendicular Magnetic Field ◽

Face Centered Cubic ◽

Lattice Image ◽

X Ray ◽

Field Annealing ◽

Face Centered

In this study, [Co/Ni]2/PtMn thin films with different PtMn thicknesses (2.7 to 32.4 nm) were prepared on Si/SiO2 substrates. The post-deposition perpendicular magnetic field annealing (MFA) processes were carried out to modify the structures and magnetic properties. The MFA process also induced strong interlayer diffusion, rendering a less sharp interface between Co and Ni and PtMn layers. The transmission electron microscopy (TEM) lattice image analysis has shown that the films consisted of face-centered tetragonal (fct) PtMn (ordered by MFA), body-centered cubic (bcc) NiMn (due to intermixing), in addition to face-centered cubic (fcc) Co, Ni, and PtMn phases. The peak shift (2-theta from 39.9° to 40.3°) in X-ray diffraction spectra also confirmed the structural transition from fcc PtMn to fct PtMn after MFA, in agreement with those obtained by lattice images in TEM. The interdiffusion induced by MFA was also evidenced by the depth profile of X-ray photoelectron spectroscopy (XPS). Further, the magnetic properties measured by vibrating sample magnetometry (VSM) have shown an increased coercivity in MFA-treated samples. This is attributed to the presence of ordered fct PtMn, and NiMn phases exchange coupled to the ferromagnetic [Co/Ni]2 layers. The vertical shift (Mshift = −0.03 memu) of the hysteresis loops is ascribed to the pinned spins resulting from perpendicular MFA processes.

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Mixed H2O/H2 Plasma-Induced Redox Reactions of Thin Uranium Oxide Films under UHV Conditions

Dalton Transactions ◽

10.1039/d1dt01020d ◽

2021 ◽

Author(s):

Ghada El Jamal ◽

Thomas Gouder ◽

Rachel Eloirdi ◽

Evgenia Tereshina-Chitrova ◽

Lukáš Horák ◽

...

Keyword(s):

Thin Films ◽

Photoelectron Spectroscopy ◽

Redox Reactions ◽

Uranium Oxide ◽

Oxide Films ◽

X Ray ◽

Gas Plasma

X-Ray Photoelectron Spectroscopy (XPS) has been used to study the effect of mixed H2O/H2 gas plasma on the surface of UO2, U2O5 and UO3 thin films at 400 °C. The...

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