Lithium phosphorus oxynitride (LiPON) film with high ionic conductivity, low electronic conductivity and high transparency in UV-VIS range offers the possible applications as electrolyte for optical devices, e.g. electrochromic device. In this work, the optical properties of LiPON are investigated by means of variable-angle spectroscopic ellipsometry (VASE) and optical transmission spectra. LiPON thin films with composition of Li3.13PO1.69N1.39 and ionic conductivity of 4.9x10(-6)Scm(-1) at room temperature were prepared by RF magnetron sputtering. Optical constants have been derived on multiple samples with film thickness from 400 to 2000nm in the energy range of 0.58-5.5eV. The optical bandgap (E-g) of LiPON film is shown to be 3.07eV by a Tauc plot. It is found that when E<E-g the Urbach exponential decay of absorption is observed. The Urbach tail width at room temperature is estimated to be 0.361eV for the LiPON film.

Lithium silicon phosphorus oxynitride (LiSiPON) thin films with different compositions have been prepared by RF magnetron sputtering in N2 by using three targets xLi2SiO3 · (1 − x) Li3PO4 with x = 0.1, 0.3, and 0.5. Compared with LiPON, the electrical properties of LiSiPON have been improved by introducing silicon. LiSiPON films deposited from the target 0.5Li2SiO3 · 0.5Li3PO4 yield the highest ionic conductivity of up to 9.7 × 10−6 S cm−1 with an activation energy of only 0.41 eV. The main mechanism for increasing ionic conductivity is the enhancement of carrier mobility. By DC polarization measurements the electronic partial conductivity was found at least seven orders of magnitude smaller than the ionic conductivity. Linear voltammetry results showed that the LiSiPON films are electrochemically stable in contact with stainless steel in the voltage range of 0–6 V. The substitution of silicon for phosphorus in the film evidenced from X‐ray photoelectron spectroscopy analysis indicated silicon in the film will create more abundant cross‐linking structures Si–O–P and (P, Si)–N < (P, Si), hence created more Li+ conducting paths which favored the higher mobility of lithium ions and larger ionic conductivity. The optical bandgap was found to decrease with increasing silicon content. We demonstrate that the prepared LiSiPON films with their larger ionic conductivity and low electronic conductivity may serve as an alternative to LiPON for applications in high energy density and high voltage lithium batteries.

Powered by TCPDF (www.tcpdf.org) This material is protected by copyright and other intellectual property rights, and duplication or sale of all or part of any of the repository collections is not permitted, except that material may be duplicated by you for your research use or educational purposes in electronic or print form. You must obtain permission for any other use. Electronic or print copies may not be offered, whether for sale or otherwise to anyone who is not an authorised user. Polity, A.; Krause-Rehberg, R.; Staab, T.E.M.; Puska, M.J.; Klais, J.; Möller, H.J.; Meyer, B.K.

The optical and electrical properties of n-type SnO2 films with high concentrations of nitrogen (SnO2:N) grown by chemical vapor deposition are studied. The carrier concentration increases from 4.1 × 1018 to 3.9 × 1019 cm−3 and the absorption edge shifts from 4.26 to 4.08 eV with increasing NH3 flow rate. Typical Urbach tails were observed from the absorption spectra and the Urbach energy increases from 0.321 to 0.526 eV with increasing NH3 flow rate. An “effective” absorption edge of about 4.61 eV was obtained for all investigated samples from fitting the extrapolations of the Urbach tails. Burstein-Moss effect, electron-impurity, and electron-electron interactions are shown to play a minor role for the shift of the absorption edges in SnO2:N thin films.

The influence of nitrogen incorporation in high concentrations on the structural properties and morphology of SnO2–xNx thin films grown by chemical vapor deposition is studied. A decrease in crystallite size and a lattice expansion in SnO2–xNx films with increasing x are found by X‐ray diffraction analysis and Raman spectroscopy. Substitutional nitrogen with a binding energy of 397.15 eV was detected by X‐ray photoelectron spectroscopy, attributed to the N3− ion in the SnN bond. The increase of the N atomic concentration x in SnO2–xNx films from 0 to 7.9 at.% without phase separation with increasing NH3 flow rate during the deposition is accompanied by a decrease of O atomic concentration.

Tin dioxide (SnO2) thin films were deposited on quartz glass substrates by chemical vapor deposition using SnI2 and O-2 as reactants. The growth experiments were carried out in the substrate temperature range of 300-900 degrees C. X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, spectrophotometry and Raman spectroscopy were used to characterize the films. The films were polycrystalline with their crystallites having a preferred orientation, which was dependent on the film thickness. The average grain size increased with increasing thickness of the films. The binding energies of Sn 3d(5/2) and O 1s for all samples showed the Sn4+ and O-Sn4+ bonding state from SnO2. The absolute average transmittance of SnO2 films exceeded 90% in the visible and infrared range. The obtained SnO2 films had optical band gaps between 3.78 and 3.92 eV. (C) 2015 Elsevier Ltd. All rights reserved.

Ammonia can assume a Zn site in ZnO forming an isovalent substitutional defect, which can become an acceptor by capturing an interstitial H atom.

Tin dioxide (SnO2) thin films were grown on c-plane sapphire substrates by chemical vapor deposition using SnI2 and O2 as reactants. The growth experiments were carried out at a fixed substrate temperature of 510°C and different O2 flow rates. X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, UV–Vis–IR spectrophotometry and Hall-effect measurement were used to characterize the films. All films consisted of pure-phase SnO2 with a rutile structure and showed an epitaxial relationship with the substrate of SnO2(100)||Al2O3(0001) and SnO2[010]||Al2O3<11–20>. The crystalline quality and properties of the films were found to be sensitively dependent on the O2 flow rate during the film growth. The absolute average transmittance of the SnO2 films exceeded 85% in the visible and infrared spectral region. The films had optical band-gaps (3.72–3.89eV) that are in line with the band gap of single-crystal SnO2. The carrier concentration and Hall mobility of the films decreased from 3.3×1019 to 9×1017cm−3 and from 19 to 2cm2V−1s−1, respectively, while the resistivity increased from 0.01 to 3Ωcm with increasing of the O2 flow rate from 5 to 60sccm.

Transparent amorphous lithium phosphorus oxynitride (LiPON) thin films with different thickness have been prepared by RF magnetron sputtering at a growth rate of 14nm/min. The mean ionic conductivity of as-deposited LiPON films determined by impedance spectroscopy was 4.9 μS/cm at 22°C with the activation energy of 0.55eV. The electronic partial conductivity was measured to be 1.6×10−6 μS/cm by recording the current–time curves at a constant voltage. The optical transmission of LiPON films were measured by UV–Vis/IR spectroscopy. The prepared LiPON films on silica glass substrate showed transmission higher than 80% in the visible light range. The complex refractive index and bandgap (~2.94eV) were estimated by fitting the transmission data with the Tauc–Lorentz dielectric function model. The local structure of the film was investigated by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Both methods confirmed the incorporation of nitrogen in the matrix. Nitrogen is present in two different chemical environments, corresponding to P−N<PP and PNP. Inductively coupled plasma-optical emission spectrometry (ICP-OES) and Rutherford backscattering spectrometry (RBS) measurements showed that the composition of the LiPON film was Li3.13PO1.69N1.39. The high nitrogen content and low oxygen content appears to be responsible for the specific electrical and optical properties of the LiPON films.

Quaternary-alloy MgxZn1-xO1-ySy thin films were grown quasi-epitaxially on c-plane sapphire substrates by pulsed laser deposition. Single-phase wurtzite MgxZn1-xO1-ySy films with compositions of 0.07 < x < 0.21 and y >= 0.8 were achieved using various ceramic targets. The S contents in the quaternary alloy films were far beyond the reported solid solubility limits of S in single-phase ternary alloy ZnO1-ySy films. The bandgap of MgxZn1-xO1-ySy, inferred from optical transmission measurements, was narrower than the bandgap of MgxZn1-xO while broadened compared with that of ZnO1-ySy. The broadening effect was enhanced with the increase of Mg content. The simultaneous substitution of cation (Zn2+) and anion (O2-) by isoelectronic elements (Mg2+ and S2-) offers further flexibility for the band-gap engineering and potentially facilitates the p-type doping of ZnO. (C) 2015 AIP Publishing LLC.

Series of CuxO thin-films in the entire range of compositions 1≤x≤2 were obtained by varying the oxygen flux in an rf-sputter deposition process. Growth windows for three crystalline phases, i.e., the thermodynamically stable cuprous oxide Cu2O and cupric oxide CuO as well as the metastable paramelaconite Cu4O3, were observed. The crystalline phases persist non-stoichiometrically over a wide range of compositions. These flux-range windows are separated by ranges where highly disordered, almost amorphous material is obtained. All samples were analysed with respect to their thermoelectric properties, i.e., Seebeck coefficient, electrical, and thermal conductivity. Clear trends of these transport parameters were found and used to determine the thermoelectric figure of merit ZT. The ZT-values at room temperature are highest for the two thermodynamically stable crystalline phases CuO and Cu2O.

Thin films of doped VO2 were deposited, analyzed, and optimized with regard to their solar energy transmittance (Tsol) and visible/luminous light transmittance (Tlum) which are important parameters in the context of smart window applications in buildings. The doping with alkaline earth metals (AEM) like Mg, Ca, Sr, or Ba increased both Tsol and Tlum due to a bandgap widening and an associated absorption edge blue-shift. Thereby, the brown-yellowish color impression of pure VO2 thin films, which is one major hindrance limiting the usage of VO2 as thermochromic window coating, was overcome. Transparent thin films with excellent switching behavior were prepared by sputtering. Highly doped V1−xMexO2 (Me = Ca, Sr, Ba) kept its excellent thermochromic switching behavior up to x(Me) = Me/(Me + V) = 10 at. % doping level, while the optical bandgap energy was increased from 1.64 eV for undoped VO2 to 2.38 eV for x(Mg) = 7.7 at. %, 1.85 eV for x(Ca) = 7.4 at. %, 1.84 eV for x(Sr) = 6.4 at. % and 1.70 eV for x(Ba) = 6.8 at. %, as well as the absorption edge is blue shifted by increasing AEM contents. Also, the critical temperature ϑc, at which the semiconductor-to-metal transition (SMT) occurs, was decreased by AEM doping, which amounted to about −0.5 K/at. % for all AEM on average. The critical temperature was determined by transmittance-temperature hysteresis measurements. Furthermore, Tsol and Tlum were calculated and were found to be significantly enhanced by AEM doping. Tlum increased from 32.0% in undoped VO2 to 43.4% in VO2 doped with 6.4 at. % Sr. Similar improvements were found for other AEM. The modulation of the solar energy transmittance ΔTsol, which is the difference of the Tsol values in the low and high temperature phase, was almost constant or even slightly increased when the doping level was increased up to about 10 at. % Ca, Sr, or Ba.

Semiconducting copper oxide (CuO) gas sensing layers show a remarkable conductance behavior if exposed to hydrogen sulfide (H2S) gas at low operating temperature (180 degrees C). At first conductance decreases as expected for a p-type semiconducting metal oxide offering reducing test gas. After a certain exposure time, however, a sudden steep increase in conductance can be observed. In a first approach this behavior is explained by the formation of metallic conducting copper sulfide (CuS, degenerate p-type semiconductor) clusters which eventually form conducting pathways across the sensing layers short-circuiting the remaining CuO phase. In the field of statistical physics such behavior can be described by the so-called percolation theory. Here we present a detailed experimental and theoretical analysis of the observed effect utilizing RF-magnetron-sputtered copper oxide films with different stoichiometry (CuO, Cu4O3 and Cu2O) as model systems. The layers are exposed to H2S for different time spans and analyzed with respect to their morphology (SEM, XRD) and chemical composition (XPS, ToF-SIMS). Analysis of the transient behavior of the conductance by means of a percolation model and comparison of the results to the experimental data allow the identification of different processes. For CuO samples first the formation of different non-CuS copper-sulfur-oxygen phases is observed followed by the percolation regime with the steep conductance increase. Afterwards diffusion processes superimposing the percolation leading to a slower conductance increase and eventually the process is dominated by diffusion of copper ions from the bulk. For oxides with other stoichiometry (Cu2O, Cu4O3) no percolation regime is observed which is attributed to higher diffusion rate of copper ions weakening the percolation effect in these samples. Based on these observations a model for the electronic conductance behavior of copper oxide gas sensors under exposure to hydrogen sulfide (H2S) at temperatures below 200 degrees C is proposed. A better understanding of these systems will enable the preparation of reliable sensors with inherent thresholds. (C) 2015 Elsevier B.V. All rights reserved.

In the last years, amorphous oxide films like indium gallium zinc oxide (IGZO) received increasing attention as channel layers in thin film transistors (TFTs). First IGZO-based devices are being successfully introduced into the display market. However, there is also a strong interest to replace or substitute the resource-limited indium. Additionally, alternative oxide materials are being explored. A promising candidate is zinc-tin-oxide (ZTO) with similar properties and performance as IGZO. Typically, indium containing materials are more stable against plasma damage during the sputtering process. Therefore we studied the growth mechanism of ZTO films sputtered from novel rotatable oxide targets both experimentally and through particle-in-cell Monte-Carlo (PIC-MC) plasma simulation. Static imprints are deposited and characterized in terms of electrical and optical performance distribution in order to understand the mechanisms of plasma damage. By PIC-MC plasma simulations, possible origins of plasma damage such as negative oxygen ions are revealed and compared with the experimental data. The comparison of experimental and simulated data allows for designing improved coater geometries with respect to reduced plasma damage and increased film uniformity.

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Ion‐beam sputter‐deposition (IBSD) was used to reactively deposit tin oxide crystalline films at oxygen fluxes of 3–15 sccm and at substrate temperatures of 100–600 °C. Analysing the samples by X‐ray diffraction and Raman spectro‐ scopy yields a map of the crystalline structures in dependence on the growth parameters. In addition to SnO2, pure SnO films of high quality and an intermediate phase such as Sn2O3 or Sn3O4 can be reproducibly obtained. Thus, IBSD is, to our knowledge, the only thin‐film deposition technique verified yet to reliably produce samples in the entire composition range of tin oxides. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)

Lithium phosphorus oxynitride (LiPON) is one of the promising electrolyte material for the thin-film batteries due to its superior electrochemical stability, moderate ionic conductivity and low electronic conductivity. In addition, LiPON has a wide optical bandgap (>3 eV) which makes it transparent for UV-Vis light and suitable for using in electrochromic thin film devices. The typical value of ionic conductivity of LiPON is in the range of 0.2 to 3.3×10-6 S/cm[1]. Here we report the deposition of amorphous LiPON thin films by RF sputtering from a commercial Li3PO4 target in nigtrogen atmosphere with the ionic conductivities at room temperature as high as 6.5×10-6 S/cm with an activation energy of 0.55 eV. The average growth rate is 14 nm per minute. The electronic conductivity is found to be 2.2×10-12 S/cm. The film composition is determined to be Li3.13PO1.69N1.39by inductively coupled plasma-optical emission spectrometry (ICP-OES) and Rutherford backscattering spectrometry (RBS), which demonstrates our LiPON sample contains relatively high nitrogen content and low oxygen content. The local structure is probed by XPS and Raman spectrometry. The incorporation of nitrogen in the matrix is confirmed by both methods and the nitrogen is present in two different chemical environments corresponding to and P-N=P. The optical properties of LiPON are studied by variable-angle spectroscopic ellipsometry (SE) and transmission measurements. The LiPON film is found to have a bandgap of 3 eV and is highly transparent for UV-VIS light. The optical constants include refractive index n, extinction coefficient k and absorption coefficient α in the energy range of 0.58~5.5 eV are derived. The Urbach tail is also observed in LiPON thin films when photon energy is lower than the bandgap. For its application in electrochromic device, the WO3/LiPON half-cells are prepared and the electrochromic properties will be discussed. [1] J.F. Ribeiro, R. Sousa, J.P. Carmo, L.M. Gonçalves, M.F. Silva, M.M. Silva, J.H. Correia, Thin Solid Films 522 (2012) 85-89.

MPS-T1-15 # 1 Chemical and Biochemical Sensors Beyond Nernst Response of Sensitivity Enhancement on EIS pH Sensing Device by Multi-Programming. Aurelien Dominguez , YiTing Lin, Chao-Sung Lai* In this study, the effect of different stressing methods on an Electrolyte-Insulator-Semiconductor structure for pH sensing has been studied. The EIS device uses an intermediate trapping storage layer of silicon nitride for the high density of traps of the material. The stressing method consists in using a low field of opposite polarity to the initial stress field to have a relaxation effect on the neutral trap created during the original process [2-3] and to repeat the programming at regular interval of time. With this method we observeD a successful trapping of holes through a negative shift of the flatband voltage and an enhancement of the sensitivity beyond Nernst response, more than THE theoretical ideal case, from 30 mV/pH to 80 mV/pH. In the meantime, by multiple times programming, a great stability with double sensitivity enhancement and variation within ±2% on the sensitivity measurement suggests that this method meets the prerequisite for medical application. 1departement of electrical engineering, GRENOBLE INPPHELMA Grenoble, France 2Department of Electronic Engineering, Chang-Gung University, Taoyuan, Taiwan 3Biosensor Group, Biomedical Engineering Research Center, Chang Gung University, Taoyuan, Taiwan *Phone: +886-3-2118800 ext: 5607 Taiwan