Radio Frequency Magnetron Sputtering Method Research Articles

In-vitro experiments on bio-functional calcium phosphate based coatings on titanium dental implant

Dental implants are a revolution in dentistry, but certain deficiencies still need to be addressed. One of the most severe threats to the success of dental implants is peri-implant infection. Existing coatings on titanium (Ti-6Al-4V) alloy surfaces rapidly lose antibacterial efficacy, reducing their ability to prevent peri-implant infectious disease. The objective of this paper was to investigate the dissolution capabilities and film properties of calcium phosphate (CaP) based layers on a titanium (Ti-6Al-4V) alloy surface produced with the radiofrequency magnetron sputtering method. These coatings have demonstrated good osseointegration capability due to their similarity to bone mineral matter. The bioactive coating materials are calcium phosphate, zinc chloride, and silver nitrate. Microstructural investigations of coated components were assessed using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive (EDX) analysis, and Atomic Force Microscopy (AFM). Bacterial adhesion to biomaterials is still a major issue when it comes to medical equipment. Antimicrobial peptides have generated interest due to the rise in antibiotic-resistant bacteria. The fact that there are concerns regarding the development of antibiotic resistance due to the development of traditional antibiotics to prevent illness reflects the complexity of the matter.The coated titanium samples were inoculated in nutrient broth and incubated at 37 °C for 24 h. The samples were tested against Staphylococcus aureus and Staphylococcus epidermidis for 72 h. A standard row containing between 1 * 105 CFU ml−1 and 1 * 107 CFU ml−1of fresh exponential culture was prepared. The plates were cultured at 37 °C and shaken (100 rpm) while the OD600 was monitored every 30 min. After 24 h, Staphylococcus aureus inhibition was higher than 70% in S4, and Staphylococcus epidermidis inhibition ranged from 60 to 70% in S4. Antimicrobial activity was found in the calcium phosphate coated samples (S4) against gram-positive Staphylococcus epidermidis and Staphylococcus aureus bacteria. The antimicrobial evaluation showed that titanium made with bioactive coating inhibited bacterial growth and biofilm formation.

Growth, Characterization, and Application of Vertically Aligned Carbon Nanotubes Using the RF-Magnetron Sputtering Method.

The aim of this work is to synthesize and characterize a nanostructured material with improved parameters suitable as a chemiresistive gas sensor sensitive to propylene glycol vapor (PGV). Thus, we demonstrate a simple and cost-effective technology to grow vertically aligned carbon nanotubes (CNTs) and fabricate a PGV sensor based on Fe2O3:ZnO/CNT material using the radio frequency magnetron sputtering method. The presence of vertically aligned carbon nanotubes on the Si(100) substrate was confirmed by scanning electron microscopy and Fourier transform infrared (FTIR), Raman, and energy-dispersive X-ray spectroscopies. The uniform distribution of elements in both CNTs and Fe2O3:ZnO materials was revealed by e-mapped images. The hexagonal shape of the ZnO material in the Fe2O3:ZnO structure and the interplanar spacing in the crystals were clearly visible by transmission electron microscopy images. The gas-sensing behavior of the Fe2O3:ZnO/CNT sensor toward PGV was investigated in the temperature range of 25-300 °C with and without ultraviolet (UV) irradiation. The sensor showed clear and repeatable response/recovery characteristics in the PGV range of 1.5-140 ppm, sufficient linearity of response/concentration dependence, and high selectivity both at 200 and 250 °C without UV radiation. This is a basis for concluding that the synthesized Fe2O3:ZnO/CNT structure is the best candidate for use in PGV sensors, which will allow its further successful application in real-life sensor systems.

Preparation and characterization of hydroxyapatite coating by magnetron sputtering on Mg–Zn–Ag alloys for orthopaedic trauma implants

The aim of the present paper was to evaluate the effect of hydroxyapatite coatings on the two types of Mg–Zn–Ag alloys as a possible solution to control magnesium alloy degradation. The coatings were prepared by the radio frequency magnetron sputtering method at a deposition temperature of 300 °C. To perform this evaluation, the coated alloys were immersed in a simulated body fluid solution at body temperature (37 ± 0.5 °C) to determine the corrosion resistance through electrochemical and immersion tests. Moreover, the investigation also consisted of the evaluation of microchemical, mechanical, and morphological properties. The deposition temperature of 300 °C was enough to obtain a crystalline hydroxyapatite structure with a Ca/P ratio close to the stochiometric one. The adhesion of coatings was not influenced by the nature of Mg–Zn–Ag alloys, so similar values for both coated alloys were found. The results showed that the coating was homogonous deposited on the Mg–Zn–Ag alloys and the corrosion resistance of uncoated magnesium alloys was improved.

High optoelectronic quality of AZO films grown by RF-magnetron sputtering for organic electronics applications

Aluminum-doped zinc oxide thin films, known by the acronym AZO, were grown by radio-frequency magnetron sputtering method (rf-magnetron sputtering) onto glass substrate at room temperature and without posterior heat treatment. The impact on the structural, electrical, and optical properties of the AZO films was studied as a function of the following deposition parameters: working pressure, rf-power and thickness. Our films showed low electrical resistivity and high transmittance in the visible region comparable to commercial indium tin oxide (ITO) films. We obtained an optimized AZO film with an electrical resistivity of 4.90 × 10−4 Ωcm and presented optical transmittance strikingly high for such a good conductor, with about 98% at 580 nm and an average optical transmittance of about 92% in the visible region. We also built and characterized an organic light-emitting diode (OLED) using the optimized AZO film as a transparent electrode. The AZO-based OLED showed characteristics comparable to a reference ITO-based device, indicating that AZO films have optoelectronic properties good enough to be used in organic electronics. In addition, the results suggest that they are suitable to be employed as transparent conductors in flexible polymeric substrates since their synthesis was performed without intentional heating.

IGZO thin-film transistors with tunneling contacts: towards power efficient display

We report the fabrication and characterization of indium gallium zinc oxide (IGZO) tunneling thin-film transistors. Both the IGZO channel and an Al2O3 tunneling barrier layer were deposited using the radio-frequency magnetron sputtering method. Compared with a conventional device, our device exhibited rapid saturation at a much smaller drain bias. Interestingly, we observed two different current saturation mechanisms within a single device, which can be explained as competition between the depletion envelope near the source electrode and channel depletion near the drain electrode. This work represents an industry-friendly method for implementing the tunnel-contact approach in the display industry.

Thermoelectrical Properties of ITO/Pt, In2O3/Pt and ITO/In2O3 Thermocouples Prepared with Magnetron Sputtering

ITO/Pt, In2O3/Pt and ITO/In2O3 thermocouples were prepared by the radio frequency (RF) magnetron sputtering method. The XRD results showed that all the annealed ITO and In2O3 films annealed at high temperature present a cubic structure. Scanning electron microscope results showed that the thickness of the ITO and In2O3 films could reach 1.25 µm and 1.21 µm, respectively. The ITO/Pt and In2O3/Pt thin film thermocouples could obtain an output voltage of 68.7 mV and 183.5 mV, respectively, under a 900 °C temperature difference, and at the same time, the Seebeck coefficient reached 76.1 µV/°C and 203.9 µV/°C, respectively. For the ITO/In2O3 thermocouple, the maximum value of the output voltage was 165.7 mV under a 1200 °C temperature difference, and the Seebeck coefficient was 138.1 µV/°C. Annealing under different atmosphere conditions under 1000 °C, including vacuum, air and nitrogen atmospheres, resulted in values of the Seebeck coefficient that were 138.2 µV/°C, 135.5 µV/°C and 115.7 µV/°C, respectively.

Improvement of the uniformity of structural and electrical properties of transparent conductive Al-doped ZnO thin films by inductively coupled plasma-assisted radio frequency magnetron sputtering

Transparent conductive Al-doped Zinc oxide thin films were deposited on glass substrates by conventional radio frequency magnetron sputtering (C-RFMS) and inductively coupled plasma-assisted radio frequency magnetron sputtering (ICP-RFMS) methods. The structural and electrical properties of films were studied as a function of the radial position (r) of the substrate in both methods. A good thickness uniformity was obtained in ICP-RFMS, while a significant decrease in film thickness was observed at r=30mm (erosion zone) in C-RFMS. The c-axis orientation was achieved in all positions in ICP-RFMS, while crystallinity was degraded at r≥25mm in C-RFMS. Low resistivity ρ of the order of 10−4Ωcm was obtained at all positions in ICP-RFMS, while ρ was rapidly increased at r≥30mm in C-RFMS. In ICP-RFMS, high-energy ion bombardment is suppressed due to the modified plasma density profile and lower space potential. As for transparency, the sample prepared at r=0mm in ICP-RFMS showed an average visible transmittance of 81%, higher than that in C-RFMS. Throughout the study, it was demonstrated that ICP-RFMS method was promising to improve the radial distribution of structural, electrical, and optical properties of Al-doped ZnO thin films.

Germanium decorated on three dimensional graphene networks as binder-free anode for Li-ion batteries

Three-dimensional (3D) graphene networks are successfully fabricated on nickel (Ni) foam by the chemical vapor deposition (CVD) technique. Amorphous Ge layer is then deposited on the 3D graphene supporting skeleton via the facile radio frequency magnetron sputtering (RFMS) method. The Ge decorated on the 3D graphene (3D Ge@Gr) networks deliver improved electrochemical performance when employed as anode for lithium ion batteries (LIBs), which is obvious superior than the two dimensional Ge nanoelectrode directly coated on the bare Ni foam (2D Ge). Significantly enhanced electrochemical cyclability upon 1500 long-term cycles under the higher current density of 1.2 mA cm−2 is accomplished in the optimized 3D Ge@Gr hybrid electrode. The interconnected 3D graphene with enlarge surface area can not only effectively provide enough space to buffer the volume change of the Ge anode during cycling, but also bring improved electrical/ionic conductivity to promote the electrochemical kinetics, thus eventually bring superb stable cyclability.

P-type β-Ga2O3 films were prepared by Zn-doping using RF magnetron sputtering

The XRD patterns show that the peak position of the Zn-doped β-Ga 2 O 3 films shifts to lower angles with the substrate temperature decreasing from 700℃ to room temperature, indicating the incorporation of Zn into Ga 2 O 3 films. Because the ion radius of Ga 3+ is 0.61Å and Zn 2+ is 0.74Å, the lattice spacing expanses with the increase of Zn concentration and thus the diffraction angle of the characteristic peak becomes smaller. The photoelectric response measurements show that the Zn-doped β-Ga 2 O 3 film based photodetectors manifest much lower dark-current and higher photo-to-dark current ratio. • P-type Ga 2 O 3 films were obtained by Zn doping using radio frequency magnetron sputtering method. • The doping concentration of Zn has a close relationship with temperature. • Zn-doped β-Ga 2 O 3 based photodetector manifested much lower dark-current and higher photo-to-dark current ratio. Zn-doped Ga 2 O 3 films were prepared using RF magnetron sputtering method at various deposition temperatures. Hall measurement demonstrated the present Zn-doped β-Ga 2 O 3 film was p -type conductivity. The XRD and XRF measurements showed the Zn dopant concentration increased with the decrease of temperature so that the position of the characteristic peak shifted to lower angles. The UV absorption spectra showed that the bandgaps became narrower with the doping concentration of Zn atom increasing. The pure and Zn-doped β-Ga 2 O 3 films were used to fabricate the photodetectors with MSM structure, respectively. The photoelectric response measurements showed that the Zn-doped specimen manifested much lower dark-current and higher photo-to-dark current ratio, but slower photoresponse speed.

Preparation and electrical transport properties of TiO thin films

Titanium monoxide has attracted great attention due to its unique superconducting characteristics and potential applications in microelectronics. In this work, a series of TiO thin films are prepared at room temperature by using the radio frequency magnetron sputtering method through changing the oxygen partial pressures. The crystal structures, valences of the elements, and electrical transport properties of the films are investigated systematically. X-ray diffraction results indicate that the films are epitaxially grown on MgO single crystal substrates along the [001] direction. After the surface of the TiO film is treated by ion etching, it is found that the Ti element mainly exists in a divalent form. For all films, the temperature coefficients of resistance are negative above superconducting transition temperature <i>T</i><sub>c</sub>. The films prepared under high oxygen partial pressures reveal insulator characteristics, and the temperature dependence of resistivity obeys the Mott-type variable-range-hopping law in low temperature regime. The films prepared under low oxygen partial pressures exhibit metallic properties, and enter into a superconducting state at low temperature. The superconducting transition temperature <i>T</i><sub>c</sub> in our film can be as high as 3.05 K. The carrier concentrations of the films are in the vicinity of ~2.0×10<sup>22</sup> cm<sup>–3</sup>, which is comparable to those for the typical metals. Interestingly, it is found that the main species of the charge carriers in the films transforms from electrons to holes with the oxygen partial pressure decreasing. The crossover of the species of the charge carriers could related to the changing of energy-band structure with the oxygen content in TiO film.

Nanoscale surface dynamics of RF-magnetron sputtered CrCoCuFeNi high entropy alloy thin films

High entropy alloy (HEA) thin films of CrCoCuFeNi are grown on stainless steel substrate using radiofrequency (RF) magnetron sputtering method at different sputtering times (30, 60 and 90 minutes), substrate temperatures (room temperature, 100 and 200 deg. Celsius) and RF powers (100, 150 and 200 W). The nanoscale morphology and topography of the thin films are obtained using an atomic force microscopy (AFM) method. The average surface roughness, interface width, fractal and multifractal characteristics of the films are presented. It is shown that the average surface roughness and interface width decrease with the time of deposition while considering the combination of the other factors. The autocorrelation and height-height correlation functions reveal that these surfaces are self-affine and exhibit fractal characteristics. The increase in sputtering power, with different combinations of time and temperature, is related to large fractal dimension and small lacunarity coefficient. The increase in substrate temperature (for different combinations with time and RF power) is shown to enhance the spatial roughness of the HEA thin films. A multifractal analysis undertaken using generalized fractal dimension, mass exponent against moment order and multifractal spectrum reveal that all the films have a multifractal character; and the films deposited at high temperatures and powers exhibit the strongest multifractal behaviour.

H2S gas sensing properties in polysilicon control-gate FET-type gas sensor

H2S gas sensing characteristics of a polysilicon control-gate (CG) FET-type gas sensor are investigated. The 15 nm thick In2O3 deposited using a radio frequency magnetron sputtering method is used as the sensing material. The metal CG is modified to poly-silicon CG, and the gas sensor with polysilicon control-gate operates well without any problems. The modified FET-type gas sensor has two CG terminals (VCG1 and VCG2), and the gas sensor with opened VCG2 shows better gas sensing characteristics by means of higher transconductance (gm) than gas sensor with grounded VCG2. H2S gas sensing characteristics are examined while varying the operating temperature, the concentration of the H2S gas, and the pre-bias voltage (Vpre). The sensing mechanism for detecting the H2S gas in an FET-type gas sensor is examined. The polysilicon control-gate FET-type gas sensor is able to detect up to 5 ppm of H2S gas. The FET-type gas sensor shows significantly improved gas response by using the pre-bias scheme.

Comprehensive growth and characterization study of GeOx/Si

In this study, the reactive radio frequency magnetron sputtering (RFMS) method under varying thickness was used to deposit GeOx on Si substrate at room temperature. The effect of thickness on the structural and optical properties of high-quality germanium dioxide (GeO2) thin films have been investigated by experimental. Structural properties were investigated using X-ray diffraction. It has been observed that the peak intensity of (113) reflection is the highest in the spectrum of 240.22 nm thickness and using scanning electron microscope (SEM) to calculate thickness of different samples. Reflection measurement, which is one of its optical properties, was measured with an optical spectrophotometer. It has been observed that as the thickness increases, the total reflectance changes. The absorption coefficient was calculated using the diffuse reflection curve. From this point of view, the energy band gap was calculated and it was seen that it varies between 4.1 eV and 4.4 eV. As a result, it was observed that the energy band gap increased as the thickness increased. And using spectroscopic ellipsometry to calculate the thickness of different, refractive index, extinction coefficient, and oscillator parameters. The oscillator energy decrease as the thickness of films increases and the dispersion energy increase with the increase of thickness. It have been observed that the thickness varies between 174.29 nm and 332.16 nm. The refractive index increases as the thickness increases.

Structural, morphological and temperature-tuned bandgap characteristics of CuS nano-flake thin films

Copper sulfide (CuS) thin films were produced by radio-frequency (RF) magnetron sputtering method. Structural, morphological and optical characteristics of deposited CuS films were presented. X-ray diffraction pattern showed two intensive peaks associated with hexagonal crystalline structure. Scanning electron microscopy image indicated that CuS films have nano-flake structured. Raman spectrum was reported to show vibrational characteristics of the CuS nano-flake thin films. Two peaks associated with Cu–S and S–S vibrations were observed in the Raman spectrum. Transmission spectra were recorded at various temperatures between 10 and 300 K. The analyses accomplished considering Tauc expression demonstrated that direct bandgap energy decreases from 2.36 eV (at 10 K) to 2.22 eV (at 300 K). Temperature-bandgap dependency was analyzed considering Varshni and Bose-Einstein expressions to reveal bandgap at 0 K, rate of change of bandgap and Debye temperature. CuS nanoflake thin film may be used in optoelectronic and photocatalysis applications thanks to its direct and narrow bandgap energy characteristics.

Interfacial charge transfers and carrier regulation characteristics of narrow/wide band gap TMDs@Ga2O3 n-n heterojunction film

The application of transition metal dichalcogenides (TMDs) in many optical devices has been seriously limited by its narrow band-gap and high electron-hole recombination rate. Therefore, more studied are desired for exploring the novel TMDs/Ga2O3 heterostructures with excellent photoexcitation properties and interfacial dynamics. Herein, the WSe2/Ga2O3 and MoS2/Ga2O3 heterostructures were successfully prepared by a two-step radio frequency magnetron sputtering method. The growth mechanism and interfacial charge transfer of the wide and narrow TMDs/Ga2O3 heterostructures are considered. The X-ray diffraction results show that the (002) orientation of the WSe2 and MoS2 was suppressed, which can be attributed to interfacial interaction. Compared to pure TMDs, the A1 g was blue-shifted in the Raman spectrum for the proposed heterostructures, which is related to the decrease of the electron density. The photoluminescence emission of TMDs/Ga2O3 heterostructures was enhanced mainly due to the transition from trions recombination to exciton recombination. Meanwhile, the transmission properties of electrons under the built-in electric field are further confirmed by the transient absorption spectroscopy. Effective charge separation not only reduces radiation emission rate but also significantly enhances the nonlinear optical response of TMDs. An open-aperture Z-scan measurement was carried out to confirm that Ga2O3 is a promising candidate for enhancing the saturable absorption or reverse saturable absorption of TMDs.

Surface, Structural, and Mechanical Properties Enhancement of Cr2O3 and SiO2 Co-Deposited Coatings with W or Be.

Direct current (DC) and radio frequency (RF) magnetron sputtering methods were selected for conducting the deposition of structural materials, namely ceramic and metallic co-depositions. A total of six configurations were deposited: single thin layers of oxides (Cr2O3, SiO2) and co-deposition configurations (50:50 wt.%) as structural materials (W, Be)—(Cr2O3, SiO2), all deposited on 304L stainless steel (SS). A comprehensive evaluation such as surface topology, thermal desorption outgassing, and structural/chemical state was performed. Moreover, mechanical characterization evaluating properties such as adherence, nano indentation hardness, indentation modulus, and deformation relative to yielding, was performed. Experimental results show that, contrary to SiO2 matrix, the composite layers of Cr2O3 with Be and W exhibit surface smoothing with mitigation of artifacts, thus presenting a uniform and compact state with the best microstructure. These results are relevant in order to develop future dense coatings to be used in the fusion domain.

Enhancement of n-type conductivity of hexagonal boron nitride films by in-situ co-doping of silicon and oxygen

Effective doping of ultra-wide band gap semiconductors is of crucial importance, yet, remains challenging. Here, we report the enhancement of n-type conductivity of nanocrystalline hexagonal boron nitride (h-BN) films with simultaneous incorporation of Si and O while deposition by radio frequency magnetron sputtering method. The resultant h-BN films are of ∼50 nm in thickness, containing nitrogen vacancy (VN) defects. Incorporation of O together with Si results in effective healing of VN defects and significantly reduces electric resistivity in h-BN thin films. X-ray photoelectron spectroscopy results reveal that under B-rich condition, the substitutional O in VN bonding with B leads to the formation of Si–N, which thus plays an important role to the n-type conductivity in h-BN films. The temperature dependent electrical resistivity measurements of the Si/O co-doped h-BN films reveal two donor levels of 130 and 520 meV at room temperature and higher temperatures, respectively. The n-h-BN/p-Si heterojunctions demonstrate apparent rectification characteristics at room temperature, where the tunneling behavior dominates throughout the injection regimes due to the effective carrier doping. This work proposes an effective approach to enhance the n-type conductivity of h-BN thin films for future applications in electronics, optoelectronics and photovoltaics.

Fabrication of high sensitivity and fast response IR photodetector based on VO2 nanocrystalline thin films prepared on the silicon substrate

On Si substrates, vanadium dioxide nanocrystalline thin films (VO2 NC-TH) were prepared using the radio frequency magnetron sputtering (RF) method. The very small particles reference film was a very thin surface that appeared smooth like a coated Si wafer with the same spherical particle prominent and irregularly distributed in a thin film, according to XRD patterns with narrow peaks intensity and field emission scanning electron microscopy (FESEM) images. The current-voltage characteristic of metal-semiconductor-metal (M-S-M) VO2 NC-TH infrared photodetectors (IR-PD) in the dark and irradiated with 850 nm light and intensity was (0.17) mW/cm2. IR-PD exhibits 603, 3567, 10081, and 17751 sensitivity at 2, 3, 4, and 5 bise voltage, with increasing bias voltage increasing quantum efficiency, responsivity, and detectivity. The responsitivity and detectivity under 2, 3, 4, and 5 V bias are (0.24, 1.58, 7.92, and 14.76) A/W and (0.176, 1.03, 3.81 and 6.98) x 1012 Jones, respectively.

Magnetic and optical properties of ZnO/Ni/ZnO multilayer film on Si(100) and sapphire substrates

The optical absorption, band gap, and magnetic properties of ZnO/Ni(t)/ZnO multilayer film structures were investigated in various Ni layer thicknesses and substrates. We deposited 1, 4, and 5 nm of Ni film by thermal evaporation technique that sandwiched between ZnO films (~15 nm) via radio frequency magnetron sputtering method on both Si(100) and sapphire substrates. Although x-ray diffraction (XRD) analysis confirmed the (002) crystalline plane of ZnO without any Ni crystal phases on Si(100) surface, the better crystalline directions of ZnO, hexagonal wurtzite structure, was observed on the sapphire substrate. In the XRD analysis, we observed the cubic structure of NiO film formation due to thermally oxidation of Ni ions with interactions ZnO layer. Atomic force microscopy images confirmed the effect of the Ni layer on the average island size of 23.9 ± 2.9 nm and 25.6 ± 6.2 of ZnO films on 4 and 5 nm Ni films, respectively. Energy dispersive x-ray spectroscopy data confirmed that there is no other atom or impurity in the sample structure. The optical transparency of the multilayer films was reduced with increasing Ni layer thickness and maximum transparency was obtained as 97% at 800 nm of wavelength for the film with 1 nm Ni. The direct optical band gap of ZnO/Ni(t)/ZnO films was found to be 3.25, 3.20, and 3.12 eV with the contribution of 1, 4, and 5 nm Ni film in the multilayer film stack. The maximum Hc is found to be 1000 Oe for Si substrates and this value is reduced to around 400 Oe due to the crystal formation of the NiO layer for sapphire substrate samples.

Gas Sensor Based on ZnO Nanostructured Film for the Detection of Ethanol Vapor

In this paper, the ZnO<La> target was synthesized by the solid-state reaction method and a nanostructured thin film was deposited by the RF (radio frequency) magnetron sputtering method on a Multi-Sensor-Platform. The obtained ZnO<La> nanostructured film was investigated as the sensing material. Energy-Dispersive X-ray (EDX) analysis indicated the existence of La in the synthesized ZnO<La> material. Scanning Electron Microscope (SEM) images of the film showed the grain sizes in the range of 20–40 nm. Sensor performance characteristics such as a dynamic response, response and recovery times, and ethanol detection range were investigated at 50–300 °C. A sensitivity was observed at extremely low concentrations of ethanol (0.7 ppm). The minimum response and recovery times of the sensor corresponding to 675 ppm ethanol vapor concentration at 250 °C were found to be 14 s and 61 s, respectively. The sensor showed a high response, good selectivity, fast response/recovery behavior, excellent repeatability toward ethanol vapor, and low sensitivity toward humidity. These characteristics enable the use of a ZnO<La> based sensor for ethanol detecting applications.