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Visible-light absorption is a critical factor for photocatalyst activity and absorption of electromagnetic (EM) interference application. The band gap of Fe2O3 is 2 eV, which can be increased by doping with a high-band-gap material such as carbon from activated carbon (AC) with a band gap of 4.5 eV for increased visible-light absorption. The porosity decreases from 88 to 81.6%, and the band gap increases from 2.14 to 2.64 eV by increasing the AC from 10 to 25%, respectively. The photocatalytic activity takes 120 min to produce a harmless product for 10-20% AC, but 25% AC shows 89.5% degradation in only 90 min and the potential to attenuate the EM wave up to 99% due to the RL being below -20 dB. The second- and third-cycle degradation achieved by the composite Fe2O3-AC having 25% AC is 88.2 and 86.5% in 90 min, respectively. The pore of the surface state of AC contains a trapped charge, and interaction occurs between the charge (electron/hole) and O2 or H2O to produce OH and superoxide (O2 -) radicals. These radicals move inside the molecule of the pollutant (methylene blue (MB)) to break up the bond, with the final products being H2O and CO2. The X-ray photoelectron (XPS) spectra show that oxygen plays a key role in the interatomic bonding with Fe, C, and MB atoms. The best absorption of EM interference is -21.43 dB, with degradation reaching 89.51% in only 90 min for 25% AC due to its higher band gap and anisotropy constant. Fe2O3-carbon is a multifunctional material for the green environment because of its electromagnetic interference absorption and photodegradation of wastewater.

Effect of post annealing temperature on electronic properties of Ga-In-Zn-O (GIZO) have quantitatively studied by using reflection electron energy loss spectroscopy (REELS), x-ray photoelectron spectroscopy (XPS), and x-ray absorption fine structure (XAFS) spectra. The band gap values of GIZO are 3.1 eV, 3.5 eV, and 3.8 eV, at room temperature (as deposited), post-annealing at 600 °C, and 700 °C, respectively. The composition of Ga increased and Zn reduced with increasing post-annealing temperature. The formation of Ga-(Ga,Zn) and Zn-(Zn,Ga) bonds in GIZO thin film annealed at 700 °C was confirmed by XAFS study. The electronic properties of GIZO thin films strongly affected by the bonding formation of Zn-O and Ga-O as the effect of annealing temperature.

In this study, we aimed to evaluate long-term condylar remodelling in skeletal Class III patients who underwent bimaxillary orthognathic surgery using cone-beam computed tomography (CBCT). Twenty-three patients were studied retrospectively, and a total of 4 CBCT scans were obtained for each subject: 1 month before surgery (T0), immediately after the surgery (T1), 6 months after the surgery (T2), and 6.1 (±2.1 years after the surgery) (T3). Condylar remodelling was measured using the condylar volume, height, width, and depth. To examine a significant change, a one-way repeated measures analysis of variance was performed. The correlation between postoperative skeletal movement and condylar volume was assessed using Spearman's correlation analysis. Condylar volume and height showed a significant decrease from T1 to T2 but a significant increase from T2 to T3. Furthermore, a significant decrease was observed between T1 and T3. The condylar width and depth showed no significant changes. Postoperative skeletal movement showed no correlation with the change in condylar volume. The change in condylar volume mostly occurred as the condylar height changed. However, it did not contribute much to the postoperative skeletal movement.

This study analyzes the total cost of saving electricity (TCSE) of energy efficiency (EE) market pilot project granting incentives for the installation of 11 high-efficiency energy appliances in 51 business sites selected in 2019 in Korea. We calculate TCSE composed of participant and program costs in ex-ante perspectives as a whole, by each efficient measure, and by each business site. The weighted average of TCSE is calculated as 2.98 ¢/kWh, which is lower than the LCOE calculated based on the installation of additional power generation sources in Korea. Additionally, excluding 2 of the 11 target technologies that were rarely introduced, the TCSE showed less than 10 cents/kWh, and it was confirmed that most of the total energy savings of the program around 84,630 MWh were achieved with these inexpensive technologies. We believe that these findings have profound implications on Korea's energy efficiency programs and policy analysis.

Electronic properties of composite Fe3O4 carbonaceous absorber materials were obtained by using X-ray photoelectron spectroscopy (XPS), reflection electron energy loss spectroscopy (REELS), and Fourier transforms infrared spectroscopy (FTIR). The bandgap of composite was increasing slightly from 2.5 eV for 10% activated carbon (AC) to 2.9 eV for 25% AC. The increase in the band-gap of the composite confirms; the bonding formation by the charge transfer complex between surface hydroxyl groups of Fe3O4 and carbonaceous in the form of AC particle. From the REELS, XPS, and FTIR shows effective orbital hybridization between the 2p(O), π(C) orbitals of amorphous carbon and 3d (Fe) orbital of Fe3O4 could lead to strong bonding formation of O-C-Fe1-x-O. For all composites shows reflection loss (R) values less than -10 dB can be designed to attenuate EM wave, thus the composites in this study are very promising for new types of EM wave absorptive materials.

An advanced organic photodetector (OPD) with a butter layer of Si-rich silicon oxynitride (SiOxNy) was fabricated. The detector structure is as follows: Indium tin oxide (ITO) coated glass substrate/SiOxNy(10 nm)/naphthalene-based donor:C60(1:1)/ITO. Values of x and y in SiOxNy were carefully controlled and the detector performances such as dark current and thermal stability were investigated. When the values of x and y are 0.16 and 0.66, the detector illustrates low dark current as well as excellent thermal stability. In the OPD, silicon oxynitride layer works as electron barrier under reverse bias, leading to the decrease of dark current and increase of detectivity. Since the band gap of silicon oxynitride unlike conventional buffer layers can also be controlled by adjusting x and y values, it can be adapted into various photodiode applications.

Composition dependence of the dielectric and optical properties of (HfZrO 4 ) (1 − x ) (SiO 2 ) ( x ) (0 ≤ x ≤ 0.2) gate dielectric thin films, grown on Si(100) by the atomic layer deposition method, was investigated by means of reflection electron energy loss spectroscopy (REELS). The quantitative analysis of REELS spectra was carried out by using the QUASES-XS-REELS and QUEELS-e( k , ω )-REELS software, which determine the dielectric function and optical properties through an analysis of experimental REELS in terms of a simulated energy loss function (ELF). For HfZrO 4 , the ELF showed peaks in the vicinity of 10.5, 15.6, 18, 21.5, 26.7, 34.5, 39.5, 46.5 and 57 eV. For HfZr-silicates with low SiO 2 concentration (x = 0.10 and 0.15), the peak positions were similar to those of HfZrO 4 , but for x = 0.20, the number of peaks were reduced and are at 14.8, 23.5, 34.5, 40.5, and 46.5 eV. These peaks originate from the superposition among d electron states of Zr, f electron states of Hf and p electron states of Si. The strength of the peak at 46.5 eV decreased as we increased the amount of SiO 2 in the compounds, which indicates that it is due to excitation between Hf 4f and Zr 3d electron states. Changes in the complex dielectric function, optical properties and band gap related to the SiO 2 concentration in the films were discussed systematically. In addition, the inelastic mean free path (IMFP) was also calculated from the determined dielectric function. The IMFP of the HfZr-silicates increased with increasing SiO 2 content and with increasing primary energy. This method is of high importance in terms of determining the dielectric and optical properties and inelastic mean free path from REELS spectra. The advantage of the method applied here is that no information on the morphology and components of the sample is required. This means that this method presented here turned out to be a convenient and efficient tool for investigation of optical properties and inelastic mean free path of ultrathin high- k alloy materials.

We investigated the relationship between band alignments and threshold voltage shifts of GaInZnO (GIZO) thin films grown on SiO2/p++-Si by the RF sputtering method via utilizing X-ray photoelectron spectroscopy and reflection electron energy loss spectroscopy. The band gap energies of the GIZO thin films are increased from 3.03 eV to 3.43 eV with the increase in their Gallium (Ga)/Indium (In) ratios of 0.83, 1.05, and 1.34. The barrier height of GIZO/Mo is also increased by increasing in the Ga/In ratio, and then the threshold voltages positively shift. From the result of DLTS, it is found that the D defect is located at 0.56 eV below the conduction band, and its defect density shows the increasing tendency by the increase in the ratio of Ga/In (i.e. the decrease in In content). From the transfer curves of the GIZO thin films, the mobility shows the decreasing tendency by the increase in the ratio of Ga/In. As a result, it is suggested that the increase in the density of D defect density in the GIZO thin film plays a dominant role in the decrease in its mobility.

The dependence of electronic properties and local structure of tantalum oxide thin film on oxygen deficiency have been investigated by means of X-ray photoelectron spectroscopy (XPS), Reflection Electron Energy Loss Spectroscopy (REELS), and X-ray absorption spectroscopy (XAS). The XPS results showed that the oxygen flow rate change results in the appearance of features in the Ta 4f at the binding energies of 23.2 eV, 24.4 eV, 25.8, and 27.3 eV whose peaks are attributed to Ta1+, Ta2+, Ta3+/Ta4+, and Ta5+, respectively. The presence of nonstoichiometric state from tantalum oxide (TaOx) thin films could be generated by the oxygen vacancies. In addition, XAS spectra manifested both the increase of coordination number of the first Ta-O shell and a considerable reduction of the Ta-O bond distance with the decrease of oxygen deficiency.

The photoluminescence (PL) origin of bright blue emission arising from intrinsic states in graphene quantum dots (GQDs) is investigated. The bright PL of intercalatively acquired GQDs is attributed to favorably formed subdomains composed of four to seven carbon hexagons. Random and harsh oxidation which hinders the energetically favorable formation of subdomains causes weak and redshifted PL.

The band alignment and defect states of GaInZnO thin films grown on SiO2/Si via radio frequency (RF) magnetron sputtering were investigated by using X-ray photoelectron spectroscopy, reflection electron energy loss spectroscopy, thermally stimulated exo-electron emission and photo-induced current transient spectroscopy.The band gap via reflection electron energy loss spectroscopy was 3.2 eV. The defect states via photo-induced current transient spectroscopy and thermally stimulated exo-electron emission were at 0.24, 0.53, 1.69 and 2.01 eV below the conduction band minimum of GIZO thin films, respectively. The defect states at 0.24 and 0.53 eV are related to the field-effect mobility, and the defect stated at 1.69 and 2.01 eV is related to the oxygen vacancy defect. Copyright © 2016 John Wiley & Sons, Ltd.

The structural and the electronic properties of pentacene on modified Si (001) were investigated using scanning tunneling microscopy (STM), atomic force microscopy (AFM) and ultraviolet photoelectron spectroscopy (UPS). Dodecane was used to modify Si (001) substrates and then pentacene was deposited on dodecane/Si (001). Our STM results show a uniform distribution of aggregated dodecane molecules all over the clean Si (001). The surface structure of pentacene on dodecaene/Si (001) examined by AFM is analogous to that of pentacene on SiO2. The UPS data showed that the work function of pentacene on clean Si (001) and pentacene on modified Si (001) with dodecane was 6.41 and 5.57 eV, respectively. Our results prove that dodecane results in the work function difference between pentacene on clean Si (001) and pentacene on dodecane/Si (001).

The electrical and optical properties as well as the electronic structure of sodium-doped (Na-doped) nickel oxide (NiO) thin films were investigated using X-ray photoelectron spectroscopy (XPS), reflection electron energy loss spectroscopy (REELS), X-ray absorption near edge structure, and extended X-ray absorption fine structure. The XPS results confirmed the presence of Ni O bonds of the NiO phase for all films via the Ni 2p spectra. The NiO thin films annealed above 200 °C have both nickel oxide and nickel metal phase. The REELS spectra showed that the band gaps of NiO thin films after Na doping were decreased. Na-doped NiO thin films exhibited relatively low resistivity compared to undoped NiO thin films. In addition, the Na-doped NiO thin films deposited at room temperature have p-type conductivity with a low electrical resistivity of 11.57 Ω cm and high optical transmittance of 80% in the visible light region. Our results demonstrate that Na doping plays a crucial role in enhancing the electrical and optical properties of NiO thin films.

Nickel oxide (NiO) thin films were grown on soda-lime glass substrates by RF magnetron sputtering method at room temperature (RT), and they were post-annealed at the temperatures of 100℃, 200℃, 300℃ and 400℃ for 30 minutes in vacuum. The electronic structure, optical and electrical properties of NiO thin films were investigated using X-ray photoelectron spectroscopy (XPS), reflection electron energy spectroscopy (REELS), UV-spectrometer and Hall Effect measurements, respectively. XPS results showed that the NiO thin films grown at RT and post annealed at temperatures below 300℃ had the NiO phase, but, at 400℃, the nickel metal phase became dominant. The band gaps of NiO thin films post annealed at temperatures below 300℃ were about 3.7 eV, but that at 400oC should not be measured clearly because of the dominance of Ni metal phase. The NiO thin films post-annealed at temperatures below 300℃ showed p-type conductivity with low electrical resistivity and high optical transmittance of 80% in the visible light region, but that post-annealed at 400℃ showed n-type semiconductor properties, and the average transmittance in the visible light region was less than 42%. Our results demonstrate that the post-annealing plays a crucial role in enhancing the electrical and optical properties of NiO thin films.

The electronic properties and optical dispersion of indium zinc tin oxide (IZTO) films with different cation compositions were investigated by reflection electron energy loss spectroscopy (REELS). The REELS spectra of IZTO films revealed that the band gap varied with different Sn/Zn ratios and In content. The optical properties were examined with REELS data using Tougaard–Yubero model and the results were compared with the envelope of the transmission spectra obtained using a UV-spectrometer. The dispersion behavior of the refractive index from REELS results was studied in terms of the single-oscillator Wemple–DiDomenico model. The results showed that the different compositions of In/Zn/Sn caused a change in the dispersion parameters of IZTO thin films in contrast to the static values of refractive indices and dielectric constant which remained the same. Our work demonstrated that REELS is an efficient tool to study the optical properties of a material by obtaining the optical parameters.

We demonstrated that a flat band voltage (VFB) shift could be controlled in TiN/(LaO or ZrO)/SiO2 stack structures. The VFB shift described in term of metal diffusion into the TiN film and silicate formation in the inserted (LaO or ZrO)/SiO2 interface layer. The metal doping and silicate formation confirmed by using transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) line profiling, respectively. The direct work function measurement technique allowed us to make direct estimate of a variety of flat band voltages (VFB). As a function of composition ratio of La or Zr to Ti in the region of a TiN/(LaO or ZrO)/SiO2/Si stack, direct work function modulation driven by La and Zr doping was confirmed with the work functions obtained from the cutoff value of secondary electron emission by auger electron spectroscopy (AES). We also suggested an analytical method to determine the interface dipole via work function depth profiling.

The effect of chlorine plasma treatment on electron ic properties of GIZO grown on SiO2/Si by RF magnetron sputtering was investigated usi ng X- ray photoelectron spectroscopy (XPS), reflection el ectron energy loss spectroscopy (REELS), and secondary ion mass spectroscopy (SIMS). SIMS depth profiles indicated that the concentration of InO and ZnO on the surface was decreased after Cl 2 plasma treatment. REELS data showed that the band gap increased from 3.4 to 3.7 eV. XPS showed that Ind 5/2 and Zn2p 3/2 shifted to the higher binding energies by 0.5 eV and 0.3 eV, respe ctively. These phenomena were caused by oxygen deficiency and hydrocarbon contamination reduction as indicated by Cl atom bonding with In and Zn cations that are present on the surface after Cl 2 plasma treatment.

The electrical and optical properties of amorphous indium zinc tin oxide (a-IZTO) thin films were examined as a function of chemical composition. Effects of Sn/Zn composition ratio and In content on the electrical and optical properties of a-IZTO thin films are discussed. The electron mobility of thin film transistors with higher Sn/Zn composition ratio was dramatically improved due to a shorter zinc–zinc separation distance. The thin film transistor with the composition of In:Zn:Sn = 20:48:32 exhibits a high mobility of 30.6 cm 2 V −1 s −1 and a high on–off current ratio of 10 9 .

The electronic structure of a SiO2 thin film on a Si substrate after Ar gas cluster ion beam (GCIB) sputtering was investigated using photoemission spectroscopy whose results were compared with those obtained via mono-atomic Ar ion beam sputtering. The depth profile of the SiO2 thin film revealed that Ar ion sputtering had a great deal of influence on electronic structure of the SiO2 thin film. However, Ar GCIB sputtering under sample rotation at the grazing incident angle did not exhibit any significant transition of electronic structure of the SiO2 thin film. The valence band structure of the SiO2 thin film during Ar GCIB sputtering was almost the same as that of the as-grown SiO2 thin film. Our results showed that Ar GCIB could be useful for potential applications of oxide materials. Copyright © 2014 John Wiley & Sons, Ltd.

The abnormal interface artifact with two intense spikes was observed in secondary ion mass spectrometry depth profiling analysis of Si/Ge multilayer films by oxygen ion beam at the sputtering conditions where the Si surface is partially oxidized. The detailed step-by-step variations of the secondary ion intensities were investigated from the interface locations determined by the compositional depth profiles. Selective accumulation of the oxygen ions in the reactive Si layer and the implantation depth was suggested as the origin of the two-step interface artifact. The distances between the interfaces and the second spikes were well correlated with the implantation depth of the projected ions. Copyright © 2014 John Wiley & Sons, Ltd.

Determination of the interface locations and the layer thicknesses in SIMS depth profiling of Si/Ti multilayer films was investigated by cesium ion beam. The raw SIMS depth profiles were converted to the compositional depth profiles by the relative sensitivity factors of Si and Ti derived from the atomic fractions of a reference Si-Ti alloy film determined by Rutherford backscattering spectroscopy. The locations of the interfaces were determined by 50 at% definition in the compositional SIMS depth profiles, and the thicknesses of the Si and Ti layers were measured from the interfaces. The layer thicknesses of the Si/Ti multilayer film were also investigated by Auger electron spectroscopy depth profiling using the same process and same definition. Copyright © 2014 John Wiley & Sons, Ltd.

Microstructure and composition analysis was performed on the nitrided Ti–6Al–4V alloy by using coupled techniques of X-ray diffraction analysis and glow discharge spectroscopy. Titanium nitride (TiN x ) appeared at the outmost surface, but the low solubility of Al in the TiN x phase made Al atom to move inward. Such Al-rich phase as Ti 3 Al compound was formed by Al accumulation at the boundary between TiN x and α(N)-Ti phase (N diffusion zone). Interestingly, the Ti 3 Al had very low concentration of N, and it may inhibit N atom from diffusing inward as a diffusion barrier. The flat region of V concentration profile with about 2 at% also appeared in the region of α(N)-Ti phase because there was a solubility limit of less than 2 at% V in the α-Ti phase (hcp).

This study focused on understanding the mechanisms of the photovoltaic property changes in Zn(S,O,OH)/Cu(In,Ga)Se2 solar cells, which were fabricated via annealing, using reflection electron energy loss spectroscopy (REELS), ultraviolet photoelectron spectroscopy (UPS), low temperature photoluminescence (LTPL), and secondary ion mass spectroscopy (SIMS). A pinhole-free Zn(S,O,OH) buffer layer was grown on a CIGS absorber layer using the chemical bath deposition (CBD). When the Zn(S,O,OH) film was annealed until 200 °C, the Zn-OH bonds in the film decreased. The band gap value of the annealed film decreased and the valence band offset (VBO) value at the Zn(S,O,OH)/CIGS interface with the annealed film increased. Both results contribute to the conduction band offset (CBO) value at the Zn(S,O,OH)/CIGS interface and, in turn, yield a reduction in the energy barrier at the interface. As a result of the annealing, the short circuit current (JSC) and quantum efficiency (QE) values (400-600 nm) of the cell increased due to the improvement in the electron injection efficiency. However, when the Zn(S,O,OH) film was annealed at 300 °C, the cell efficiency declined sharply due to the QE loss in the long wavelength region (800-1100 nm). The SIMS analysis demonstrated that the Cu content in the CIGS bulk decreased and the Cu element also diffused into CIGS/Mo interface. Through LTPL analysis, it was seen that the considerable drop of the Cu content in the CIGS bulk induced a 1.15 eV PL peak, which was associated with the transition from a deep donor defect to degrade the quality of the CIGS bulk. Accordingly, the series resistance (RS) and efficiency of the cell increased.

a b s t r a c t Quantitative analysis of Cu(In,Ga)Se2 (CIGS) films with non-uniform depth distributions was investi- gated by Auger electron spectroscopy (AES) depth profiling. The atomic fractions of the CIGS films were measured by relative sensitivity factors determined by a total number counting method from a CIGS reference film certified by isotope dilution-inductively coupled plasma/mass spectrometry. In the AES depth profiling analysis of the CIGS films, the intensities of Auger electron peaks in Cu, In, Ga and Se were determined by integrating the individual Auger peak intensities in the whole depth range of the AES depth profiles. The atomic fractions measured by AES analysis were linearly proportional to the certified values. The uncertainty in the AES depth profiling analysis of CIGS films was much smaller than that in the secondary ion mass spectrometry depth profiling analysis and that in the international comparison of national metrology institutes for the quantification of Fe-Ni alloy films. © 2013 Elsevier B.V. All rights reserved.

as antistatic coatings, touch display panels, solar cells, flat panel displays, and optical coatings. We have studied the electrical and optical properties of InSnZnO thin films. The InSnZnO thin films were deposited on glass substrates by using the RF magnetron sputtering method and a target composition of In:Zn:Sn = 20:48:32. The thin films were post-annealed at 350 C for 1 hour in air. The resistivity, carrier concentration, and mobility of the InSnZnO thin films were measured by using the van der pauw method and Hall measurements. The optical properties of the InSnZnO thin films were investigated by using an UV spectrometer. After post-annealing at 350 C, the resistivity of the InSnZnO thin films was decreased, but the carrier concentration was increased, which showed that the annealing had play a crucial role in increasing the carrier concentration. The average optical transmittance of the InSnZnO thin films was greater than 80% in the visible light region. These results show that InSnZnO thin films may be useful for transparent thin-film semiconductors.

Inconel 718 super alloy was aging heat treated at the temperature range from 675°C to 785°C for 5~40 hours after solution annealing at 1025°C for 1 hour. The aging treated specimens were investigated microstructure, mechanical properties and thermal expansion/contraction. Precipitates appeared for a long time aging treatment were niobium carbide and also γ’ phase. For the aging treatment time of 10 hours, the changes in strength and hardness with increasing aging treatment temperature showed the maximum value at the temperature of 725°C. This maximum value is to be related with the precipitation of γ’ and γ’’ phases. The decrease in strength, elongation and hardness during long time aging at 725°C were thought to be induced from the coarsening of the grain size and the transformation of γ’’ phase to γ’ phase. For the specimens treated for 10 hours, impact energy showed constant value of ~105 J with increasing the aging temperature, however this value continuously decreased with elapsing time at the aging temperature of 725°C. It was found that the decrease in impact value was induced from the coarsening of grain size and the carbide coarsening. The coefficient of thermal expansion of aging treated Inconel 718 alloy increased with raising test temperature, and the coefficient was appeared 11.57~12.09 ㎛/m?°C and 14.28~14.39 ㎛/m?°C, respectively, after heating to 150°C and 450°C.

We demonstrated that a flat band voltage (VFB) shift could be controlled in TiN/(LaO or ZrO)/SiO2 stack structures. The VFB shift described in term of metal diffusion into the TiN film and silicate formation in the inserted (LaO or ZrO)/SiO2 interface layer. The metal doping and silicate formation confirmed by using transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) line profiling, respectively. The direct work function measurement technique allowed us to make direct estimate of a variety of flat band voltages (VFB). As a function of composition ratio of La or Zr to Ti in the region of a TiN/(LaO or ZrO)/SiO2/Si stack, direct work function modulation driven by La and Zr doping was confirmed with the work functions obtained from the cutoff value of secondary electron emission by auger electron spectroscopy (AES). We also suggested an analytical method to determine the interface dipole via work function depth profiling.

Electronic and optical properties of Fe–Ni alloy thin films grown on Si (1 0 0) by ion beam sputter deposition were studied via quantitative analyses of reflection electron energy loss spectra (REELS). The analysis was carried out by using the QUASES-XS-REELS and QUEELS-ɛ( k , ω )-REELS softwares to determine the energy loss function (ELF) and the dielectric functions and optical properties by analyzing the experimental spectra. For Ni, the ELF shows peaks around 3.6, 7.5, 11.7, 20.5, 27.5, 67 and 78 eV. The peak positions of the ELF for Fe 28 Ni 72 are similar to those of Fe 51 Ni 49 , even though there is a small peak shift from 18.5 eV for Fe 51 Ni 49 to 18.7 eV for Fe 28 Ni 72 . A plot of n, k, ɛ 1 , and ɛ 2 shows that the QUEELS-ɛ( k , ω )-REELS software for analysis of REELS spectra is useful for the study of optical properties of transition metal alloys. For Fe–Ni alloy with high Ni concentration (Fe 28 Ni 72 ), ɛ 1 , and ɛ 2 have strong similarities with those of Fe. This indicates that the presence of Fe in the Fe–Ni alloy thin films has a strong effect.

Defect depth profiles of Cu (In1−x,Gax)(Se1−ySy)2 (CIGSS) were measured as functions of pulse width and voltage via deep-level transient spectroscopy (DLTS). Four defects were observed, i.e., electron traps of ~0.2 eV at 140 K (E1 trap) and 0.47 eV at 300 K (E2 trap) and hole traps of ~0.1 eV at 100 K (H1 trap) and ~0.4 eV at 250 K (H2 trap). The open circuit voltage (VOC) deteriorated when the trap densities of E2 were increased. The energy band diagrams of CIGSS were also obtained using Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), and DLTS data. These results showed that the valence band was lowered at higher S content. In addition, it was found that the E2 defect influenced the VOC and could be interpreted as an extended defect. Defect depth profile images provided clear insight into the identification of defect state and density as a function of depth around the space charge region.

The relative atomic fraction of Cu(In,Ga)Se2 (CIGS) films is one of the most important measurements for the fabrication of CIGS thin film solar cells. However, the quantitative analysis of multi-element alloy films is difficult by surface analysis methods due to the severe matrix effect. In this study, the quantitative analysis of CIGS films was investigated by secondary ion mass spectrometry (SIMS). The atomic fractions of Cu, In, Ga and Se in the CIGS films were measured by alloy reference relative sensitivity factors derived from the certified atomic fractions of a reference CIGS film. The total ion intensities of the constituent elements were obtained by a total number counting method. The atomic fractions measured by SIMS were linearly proportional to those certified by inductively coupled plasma mass spectrometry using an isotope dilution method. The uncertainties were determined from the standard uncertainties in the measurements and those of a CIGS thin film certified reference material.

It has been known that the ferritic stainless steel can be changed to martensitic stainless steel whennitrogen is added. However the high hardness of martensitic stainless steel prevents the plastic deformation. Inthis study, instead of martensite, the surface microstructure was changed into nitrogen pearlite to increase theplastic deformation easily by isothermal heat treatment after high temperature gas nitriding (HTGN) the AISI 430ferritic stainless steel. The isothermal treatment was carried out at 780 o C for 4, 6, and 10 hrs, respectively, afterHTGN treatment at 1100 o C for 10 hrs. The surface layer of isothermal-treated steel appeared nitrogen pearlitecomposed with fine chromium nitride and ferrite. Hence, the interior region that was not affected by nitrogen per-meation exhibited ferrite phase. When quenching the isothermal treated steel at 1100 o C, martensitic phaseformed at the surface layer. The hardness of surface layer of isothermal-treated steel and quenched steel mea-sured the value of 150~240 Hv and 630 Hv, respectively.(Received March 27, 2012; Revised April 13, 2012; Accepted April 20, 2012)Key words: AISI430 ferrite stainless steel, HTGN, Isothermal treatment, Nitrogen pearlite

The amount, size, and spheroidization of nano-carbides were evaluated to determine their effect on the hydrogen-delayed fracture (HDF) properties of high-strength steel wires produced by quenching and tempering (QT) during high-frequency induction heat treatment. The steel wires had a microstructure of tempered martensite showing a tensile strength of 1.2 GPa. The size of the carbide decreased and the spheroidization increased with the tempering temperature. The 0.3C–Si steels that have needle-like carbides were more susceptible to HDF than the other steels (0.2C–Cr and 0.2C–Cr–Mo) that have carbides of high spheroidization rate. Calculation of the activation energy using thermal desorption spectrometry (TDS) defined the hydrogen trapping site. The trapping sites of diffusible hydrogen were the grain boundary and lath boundary for all three wires. Carbide/matrix interfaces trapped nondiffusible hydrogen for all specimens. The 0.2C–Cr steel exhibited the largest resistance to HDF because of the nano-sized and spheroidized carbide.

The electronic and optical properties of GaInZnO (GIZO), HfInZnO (HIZO) and InZnO (IZO) thin films on glass substrates were investigated using X-ray photoelectron spectroscopy (XPS) and reflection electron energy loss spectroscopy (REELS). XPS results show that HIZO, GIZO, and IZO thin films have mixed metal and oxide phases. REELS spectra reveal that the band gaps of GIZO, HIZO, and IZO thin films are 3.1 eV, 3.5 eV, and 3.0 eV, respectively. These band gaps are consistent with optical band gaps determined by UV-Spectrometer. The optical properties represented by the dielectric function ɛ , the refractive index n , the extinction coefficient k , and the transmission coefficient T of the GIZO, HIZO and IZO thin films were determined from a quantitative analysis of REELS spectra. The transmission coefficient was increased by 4% for the HIZO compound incorporating Hf into IZO, but decreased by 3% for the GIZO compound incorporating Ga into IZO in the visible region in comparison to that of IZO.

Damage profiles on Si (001) surface via argon gas cluster ion beam sputtering and mono-atomic argon ion beam sputtering were investigated using medium energy ion scattering. The surface thickness damaged by Ar cluster ion beam sputtering was approximately 10 nm for 20 keV, 6.4 nm for 10 keV, and 4.2 nm for 5 keV and the composition of the implanted Ar atoms was 0.2 at% for 20 keV and 0.1 at% for both 10 and 5 keV. The surface thickness damaged by Ar ion beam sputtering was approximately 5.3 nm for 1 keV, 8.5 nm for 2 keV, and 12 nm for 3 keV and the maximum Ar concentration of the implanted Ar atoms in the Si substrate was 5.5 at% for 1 keV, 5.8 at% for 2 keV, and 7.8 at% for 3 keV. The depth of the damaged layers after Ar ion sputtering on Si (001) is proportional to the in-depth distribution of the implanted primary Ar ions. The depth of the damaged layer after the Ar cluster ion beam sputtering did not depend on the implanted Ar atoms because the implanted Ar atoms are negligible. Understanding the details about the damage process via Ar cluster ion beam sputtering can be useful for the practical surface analysis. Copyright © 2012 John Wiley & Sons, Ltd.