scholarly journals Advanced RuO2 Thin Films for pH Sensing Application

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6432
Author(s):  
Xinyue Yao ◽  
Mikko Vepsäläinen ◽  
Fabio Isa ◽  
Phil Martin ◽  
Paul Munroe ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Ph Sensitivity ◽  
Ph Sensing ◽  
Metallic Oxide ◽  
Ph Response ◽  
Rf Discharges ◽  
Oxide Cathode ◽  
Oxide Cathodes ◽  
Substrate Temperatures

RuO2 thin films were prepared using magnetron sputtering under different deposition conditions, including direct current (DC) and radio frequency (RF) discharges, metallic/oxide cathodes, different substrate temperatures, pressures, and deposition times. The surface morphology, residual stress, composition, crystal structure, mechanical properties, and pH performances of these RuO2 thin films were investigated. The RuO2 thin films RF sputtered from a metallic cathode at 250 °C exhibited good pH sensitivity of 56.35 mV/pH. However, these films were rougher, less dense, and relatively softer. However, the DC sputtered RuO2 thin film prepared from an oxide cathode at 250 °C exhibited a pH sensitivity of 57.37 mV/pH with a smoother surface, denser microstructure and higher hardness. The thin film RF sputtered from the metallic cathode exhibited better pH response than those RF sputtered from the oxide cathode due to the higher percentage of the RuO3 phase present in this film.

scholarly journals The Properties of Zn-Doped AlSb Thin Films Prepared by Pulsed Laser Deposition

Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 136
Author(s):  
Ping Tang ◽  
Weimin Wang ◽  
Bing Li ◽  
Lianghuan Feng ◽  
Guanggen Zeng
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Band Gap ◽  
Photovoltaic Effect ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Sem Images ◽  
Glass Substrates ◽  
Substrate Temperatures

Aluminum antimony (AlSb) is a promising photovoltaic material with a band gap of about 1.62 eV. However, AlSb is highly deliquescent and not stable, which has brought great difficulties to the applications. Based on the above situation, there are two purposes for preparing our Zn-doped AlSb (AlSb:Zn) thin films: One is to make P-type AlSb and the other is to find a way to suppress the deliquescence of AlSb. The AlSb:Zn thin films were prepared on glass substrates at different substrate temperatures by using the pulsed laser deposition (PLD) method. The structural, surface morphological, optical, and electrical properties of AlSb:Zn films were investigated. The crystallization of AlSb:Zn thin films was enhanced and the electrical resistivity decreased as the substrate temperature increased. The scanning electron microscopy (SEM) images indicated that the grain sizes became bigger as the substrate temperatures increased. The Raman vibration mode AlSb:Zn films were located at ~107 and ~142 cm−1 and the intensity of Raman peaks was stronger at higher substrate temperatures. In the experiment, a reduced band gap (1.4 eV) of the AlSb:Zn thin film was observed compared to the undoped AlSb films, which were more suitable for thin-film solar cells. Zn doping could reduce the deliquescent speed of AlSb thin films. The fabricated heterojunction device showed the good rectification behavior, which indicated the PN junction formation. The obvious photovoltaic effect has been observed in an FTO/ZnS/AlSb:Zn/Au device.

Physical Characterization of Zirconium Doped Zinc Oxide Thin Firms Deposited by Spray Pyrolysis

1998 ◽  
Vol 520 ◽  
Author(s):  
A. Maldonado ◽  
D.R. Acosta ◽  
M. De La Luz Olvera ◽  
R. Castanedo ◽  
G. Torres ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Zinc Oxide ◽  
Spray Pyrolysis ◽  
Doping Concentration ◽  
Film Properties ◽  
Preferential Growth ◽  
X Ray ◽  
Substrate Temperatures

ABSTRACTZinc oxide thin films doped with zirconium were prepared from solutions with doping material dispersed at several concentrations and using the spray pyrolysis technique.The films were deposited over sodocalcic glasses at different substrate temperatures. Effects of doping material concentration and substrate temperatures on electrical, optical, structural and morphological film properties are presented. Results show an evolution in morphology and grains size as the doping concentration is increased. Preferential growth in the (002) orientation was detected for each thin film from X ray diffractograms.

Effects of Substrate Temperature on Structure and Optical Property of Cu2O:N Thin Film Deposited by Reactive Pulse Magnetron Sputtering

2014 ◽  
Vol 540 ◽  
pp. 25-29
Author(s):  
Xing Fa Zi ◽  
Wen Yang ◽  
Peng Zhi Yang ◽  
Rui Ming Liu ◽  
Xin Zhu Shu
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetron Sputtering ◽  
Substrate Temperature ◽  
Atmosphere Effect ◽  
Pulse Magnetron ◽  
Vis Spectroscopy ◽  
Structure Surface ◽  
Substrate Temperatures ◽  
Reactive Pulse

N-doped Cu2O (Cu2O:N) thin films were deposited on glass substrate by reactive pulse magnetron sputtering method using Cu target in a mixture of N2、O2and Ar atmosphere. Effect of substrate temperature on structure, surface morphology and optical properties of thin films were investigated by XRD, AFM and UV-Vis spectroscopy. The results showed that the single-phase of Cu2O(111) thin films were grown for substrate temperature < 200°C. The thin films deposited under different substrate temperatures are characteristics of 2D growth. Moreover,the optical band gap Egof thin film was in the range 2.54-2.58eV, and slightly decreased with increasing of substrate temperatures from RT to 400°C.

METAL OXIDE THIN FILMS AS PH SENSING MEMBRANE FOR EXTENDED GATE FIELD EFFECT TRANSISTOR

2016 ◽  
Vol 78 (5-8) ◽  
Author(s):  
Muhammad AlHadi Zulkefle ◽  
Rohanieza Abdul Rahman ◽  
Khairul Aimi Yusof ◽  
Wan Fazlida Hanim Abdullah ◽  
Mohamad Rusop Mahmood ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Field Effect ◽  
Field Effect Transistor ◽  
Sol Gel ◽  
Ph Sensing ◽  
Tio2 Thin Films ◽  
Suitable Material ◽  
Effect Transistor ◽  
Sensing Membrane

In this research, metal oxides (ZnO and TiO2) thin films were fabricated by the sol-gel spin coating method. The thin films were applied as the pH sensing membrane for the extended-gate field effect transistor (EGFET) sensor to distinguish the sensing capability between them. The surface morphology, thin film components and crystalline quality were characterized and the sensor performance of both materials were characterized and compared. The results showed that TiO2 thin film gave higher sensitivity with better linearity compared to the ZnO thin films hence was considered a more suitable material to be used as sensing membrane in EGFET pH sensor compared to zinc oxide. 

Effect of Post Deposition Annealing Process on the pH Sensitivity of Spin-Coated Titanium Dioxide Thin Film

2015 ◽  
Vol 749 ◽  
pp. 197-201 ◽  
Author(s):  
Rohanieza Abdul Rahman ◽  
Muhammad Al Hadi Zulkefle ◽  
Wan Fazlida Hanim Abdullah ◽  
Sukreen Hana Herman
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Titanium Dioxide ◽  
Indium Tin Oxide ◽  
Oxide Semiconductor ◽  
Constant Current ◽  
Ph Sensing ◽  
Buffer Solution ◽  
Sensing Membrane ◽  
Post Deposition

This paper presents an investigation on titanium dioxide (TiO2) thin film, which is used as sensing membrane for Extended-Gate Field Effect Transistor (EGFET) for pH sensing application. TiO2 thin films were deposited using sol-gel spin coating method on indium tin oxide (ITO) substrates. After the deposition, the thin films were annealed at 300 °C for 10 and 15 min, while another sample was annealed at 400 °C for 15 min. The sensitivity measurement was taken using the EGFET setup equipment with constant-current (100 μA) and constant-voltage (0.5 V) biasing interfacing circuit. TiO2 thin film as the pH-sensitive membrane and the working electrode was connected to a commercial metal-oxide semiconductor FET (MOSFET). The MOSFET then was connected to the interfacing circuit. The sensitivity of the TiO2 thin film towards pH buffer solution was measured by dipping the sensing membrane in pH4, pH7 and pH10 buffer solution. For comparison, a sample of bare-ITO was also tested to see its sensitivity. We found that the TiO2 thin film annealed at 400 °C for 15 min gave the highest sensitivity compared to other annealing conditions and also compared to the bare ITO substrate with the value of 44.30 mV/pH. This showed that TiO2 thin film can be used for pH sensing and the post-deposition treatment of the thin film can influence the sensing ability. We also measured the TiO2 thin films’ current – voltage (I-V) characteristics. Relating the I-V characteristic of the thin films and sensitivity, the sensing membrane with higher conductivity gave better sensitivity.

Effect of Domain Structure on the Magnetoresistance of Epitaxial Thin Films of Ferromagnetic Metallic Oxide SrRuO3

1997 ◽  
Vol 494 ◽  
Author(s):  
R. A. Rao ◽  
D. B. Kacedon ◽  
C. B. Eom
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Thin Films ◽  
Domain Structure ◽  
Applied Magnetic Field ◽  
Spin Fluctuations ◽  
Negative Magnetoresistance ◽  
Epitaxial Thin Films ◽  
Metallic Oxide ◽  
Domain Structures

ABSTRACTWe have grown epitaxial ferromagnetic metallic oxide SrRuO3 thin films with different domain structures on (001) LaAlO3 and miscut (001) SrTiO3 substrates. The effect of crystallographic domain structures on the magnetization and magnetoresistive behavior of epitaxial SrRuO3 thin films has been studied. Magnetization measurements on the single domain film on 2° miscut (001) SrTiO3 substrate showed that the in-plane [110] direction, which is aligned along the miscut direction, is the easier axis for magnetization compared to the [001] direction. This film also showed a strong anisotropie magnetoresistance (AMR) effect of ∼ 8% in magnitude. In contrast, the SrRuO3 thin film on (001) LaAlO3 substrate shows identical magnetization and magnetoresistance behavior in two orthogonal directions on the film due to the presence of 90 domains in the plane. For both the films, large negative magnetoresistance effects (-10%) were observed when the current and the applied magnetic field are parallel. The magnetoresistance behavior is explained in terms of suppression of spin fluctuations near Tc and the AMR effect.

scholarly journals Fabrication And pH Sensing Characteristics Measurement of Back Gate ZnO Thin Film Planar FET

2021 ◽  
Author(s):  
Ankita Porwal ◽  
Chitrakant Sahu
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Surface Characterization ◽  
Ph Value ◽  
Ph Sensor ◽  
Ph Sensitivity ◽  
Voltage Sensitivity ◽  
Zno Thin Film ◽  
Ph Sensing ◽  
Back Gate

Abstract Here in we demonstrate the design of a low- cost zinc oxide (ZnO) thin-film planar transistor-based pH sensor controlled by the bottom gate fabricated by a fairly simple fabrication approach. The performance of the fabricated device is evaluated by electrical as well as surface characterization. The surface morphology is analyzed by scanning electron microscope (SEM) and atomic force microscopy (AFM) and it shows surface properties that are essential for a device to function as a pH sensor. The fabricated thin-film FET comprises Zinc Oxide (ZnO) as a channel layer of length 6 µm and thickness 200 nm, Silicon Nitride (Si3N4) as a pas- sivation layer, and Aluminum (Al) as a contact layer. The effect on pH sensitivity for varied channel lengths (6 µm, 12 µm, and 15 µm) is also examined and opti- mum results have been achieved at channel length = 6 µm. The change in threshold voltage (ΔVth) & change in current (ΔImax) are used as a sensing metrics to an- alyze the sensing performance of the device. The device shows excellent pH sensitivity in terms of average cur- rent and average voltage sensitivity 120.97 mA/pH and 97.85 mv/pH respectively at pH ranging from 3.2 to 11.1 with best pH stability (linearity) for pH value 4 to 10. The voltage sensitivity is higher than the Nernstian value (59 mv/pH) at room temperature.

scholarly journals EGFET pH Sensor Performance Dependence on Sputtered TiO2Sensing Membrane Deposition Temperature

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Khairul Aimi Yusof ◽  
Rohanieza Abdul Rahman ◽  
Muhammad AlHadi Zulkefle ◽  
Sukreen Hana Herman ◽  
Wan Fazlida Hanim Abdullah
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Indium Tin Oxide ◽  
Deposition Temperature ◽  
Room Temperature ◽  
Ph Sensor ◽  
Lower Sensitivity ◽  
Ph Sensing ◽  
The One ◽  
Sensing Membrane

Titanium dioxide (TiO2) thin films were sputtered by radio frequency (RF) magnetron sputtering method and have been employed as the sensing membrane of an extended gate field effect transistor (EGFET) for pH sensing detection application. The TiO2thin films were deposited onto indium tin oxide (ITO) coated glass substrates at room temperature and 200°C, respectively. The effect of deposition temperature on thin film properties and pH detection application was analyzed. The TiO2samples used as the sensing membrane for EGFET pH-sensor and the current-voltage (I-V), hysteresis, and drift characteristics were examined. The sensitivity of TiO2EGFET sensing membrane was obtained from the transfer characteristic (I-V) curves for different substrate heating temperatures. TiO2thin film sputtered at room temperature achieved higher sensitivity of 59.89 mV/pH compared to the one deposited at 200°C indicating lower sensitivity of 37.60 mV/pH. Moreover the hysteresis and the drift of TiO2thin film deposited at room temperature showed lower values compared to the one at 200°C. We have also tested the effect of operating temperature on the performance of the EGFET pH-sensing and found that the temperature effect was very minimal.

Structures and Properties of C60 & C70 Thin Films Fabricated by Organic MBE

1992 ◽  
Vol 247 ◽  
Author(s):  
K. Tanigaki ◽  
T. Ichihsdhi ◽  
T. W. Ebbesen ◽  
S. Kuroshima ◽  
S. Iijima ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Alkali Halide ◽  
Molecular Motion ◽  
Face Centered Cubic ◽  
Reversible Change ◽  
Structures And Properties ◽  
The Face ◽  
Face Centered ◽  
Substrate Temperatures

ABSTRACTThe C60/C70 thin film crystals have been fabricated on the (001) surface of alkali halide substrates, KC1, KBr, and NaCl, and their structures have been studied. The crystal structure analyses by TEM show that the hexagonal closed packing (hep) with lattice parameters of a=10.0 Å and c=16.3 Å and the face-centered cubic (fee) with a=14.2 Å coexist in the C60 thin film crystals. The C70 thin film crystals show an expanded lattice constant of a=10.5 Å from the view perpendicular to the stacking plane. The ratio of hep to fee is dependent on the kind of the substrates and on the substrate temperatures during the crystal growth. The observed reversible change in the Raman spectrum of the C60 thin films implies a rotational molecular motion in the thin film crystals.

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