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.

PH SENSITIVITY DEPENDENCY ON THE ANNEALING TEMPERATURE OF SPIN-COATED TITANIUM DIOXIDE THIN FILMS

2016 ◽  
Vol 78 (5-8) ◽  
Author(s):  
Khairul Aimi Yusof ◽  
Rohanieza Abdul Rahman ◽  
Muhammad AlHadi Zulkefle ◽  
Sukreen Hana Herman ◽  
Wan Fazlida Hanim Abdullah
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Titanium Dioxide ◽  
Indium Tin Oxide ◽  
Ph Sensor ◽  
Tio2 Thin Films ◽  
Glass Substrates ◽  
Ito Glass ◽  
Ito Thin Films ◽  
Sensing Membrane

Titanium dioxide (TiO2) thin films were fabricated on indium tin oxide (ITO) glass substrates using the spin coating technique and further were implemented as sensing membranes of the extended gate field effect transistor (EGFET) based pH sensor. The as-deposited thin films were annealed at different temperatures from 200 - 600 °C in room ambient for 20 min. The effects of different annealing temperatures on electrical and crystalline properties were analyzed by I-V two point probes measurement and X-ray diffraction respectively. Meanwhile, the surface morphology of thin films was observed by field emission scanning electron microscope (FESEM). We then measured the transfer characteristics (ID-VG) of the TiO2/ITO sensing membrane using a semiconductor parametric device analyzer for sensor characterization. It was found that, TiO2/ITO sensing membrane annealed at 300 °C achieved higher sensitivity and good linearity of 51.48 mV/pH and 0.99415, respectively in the pH buffer solutions of 4, 7, 10, and 12. Thin film annealed at 300 °C gives higher conductivity thin film of 384.62 S/m. We found that the conductivity of TiO2/ITO thin films was proportional with the sensitivity of sensing membrane.  

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.

scholarly journals Spin Speed and Duration Dependence of TiO2Thin Films pH Sensing Behavior

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Muhammad AlHadi Zulkefle ◽  
Rohanieza Abdul Rahman ◽  
Khairul Aimi Yusof ◽  
Wan Fazlida Hanim Abdullah ◽  
Mohamad Rusop ◽  
...  
Keyword(s):  
Thin Films ◽  
Field Effect ◽  
Field Effect Transistor ◽  
Ph Sensor ◽  
Oxide Semiconductor ◽  
Ph Sensing ◽  
Spin Speed ◽  
Coating Method ◽  
Effect Transistor ◽  
Sensing Membrane

Titanium dioxide (TiO2) thin films were applied as the sensing membrane of an extended-gate field-effect transistor (EGFET) pH sensor. TiO2thin films were deposited by spin coating method and the influences of the spin speed and spin duration on the pH sensing behavior of TiO2thin films were investigated. The spin coated TiO2thin films were connected to commercial metal-oxide-semiconductor field-effect transistor (MOSFET) to form the extended gates and the MOSFET was integrated in a readout interfacing circuit to complete the EGFET pH sensor system. For the spin speed parameter investigation, the highest sensitivity was obtained for the sample spun at 3000 rpm at a fixed spinning time of 60 s, which was 60.3 mV/pH. The sensitivity was further improved to achieve 68 mV/pH with good linearity of 0.9943 when the spin time was 75 s at the speed of 3000 rpm.

scholarly journals EVALUATION ON THE EGFET PH SENSING PERFORMANCE OF SOL-GEL SPIN COATED TITANIUM DIOXIDE THIN FILM

2021 ◽  
Vol 83 (4) ◽  
pp. 119-125
Author(s):  
Muhammad AlHadi Zulkefle ◽  
Sukreen Hana Herman ◽  
Rohanieza Abdul Rahman ◽  
Khairul Aimi Yusof ◽  
Aimi Bazilah Rosli ◽  
...  
Keyword(s):  
Thin Film ◽  
Tio2 Thin Film ◽  
Drift Rate ◽  
Sol Gel ◽  
Ph Sensor ◽  
Ph Sensing ◽  
Coating Method ◽  
Effect Transistor ◽  
Sensing Membrane ◽  
Sensing Performance

For this study, TiO2 thin film was fabricated using the sol-gel spin coating method. The fabricated film was then applied as a sensing membrane in an extended gate field effect transistor (EGFET) pH sensor system. The pH sensing performance of the sol-gel spin-coated TiO2 was evaluated in terms of sensitivity, linearity, and hysteresis where the value obtained was 58.70 mV/pH, 0.9922, and 86.17 mV respectively. The drift rate of the sample when being measured for 12 consecutive hours was also determined where measurement in pH 4, pH 7, and pH 10 yield drift rate of 1.72 mV/h, 4.14 mV/h, and 6.05 mV/h respectively.  Besides that, the TiO2 was characterized for its thickness (24.32 nm) and surface roughness (5.129 nm). From the results obtained, it was found that sol-gel spin-coated TiO2 thin film with thickness between 20 - 29 nm will have high pH sensitivity (more than 50 mV/pH).

scholarly journals Etchability Dependence of InOx and ITO Thin Films by Plasma Enhanced Reactive Thermal Evaporation on Structural Properties and Deposition Conditions

MRS Advances ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 207-212 ◽  
Author(s):  
Ana Amaral ◽  
G. Lavareda ◽  
C. Nunes de Carvalho ◽  
V. André ◽  
Yuri Vygranenko ◽  
...  
Keyword(s):  
Thin Films ◽  
Structural Properties ◽  
Indium Tin Oxide ◽  
Deposition Temperature ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
Chemical Reactivity ◽  
X Ray ◽  
Ito Thin Films ◽  
Deposition Conditions

ABSTRACTIndium oxide (InOx) and indium tin oxide (ITO) thin films were deposited on glass substrates by plasma enhanced reactive thermal evaporation (PERTE) at different substrate temperatures. The films were then submitted to two etching solutions with different chemical reactivity: i) HNO3 (6%), at room temperature; ii) HCl (35%): (40 °Bé) FeCl3 (1:1), at 40 °C. The dependence of the etchability of the films on the structural and deposition conditions is discussed. Previously to etching, structural characterization was made. X-ray diffraction showed the appearance of a peak around 2θ=31° as the deposition temperature increases from room temperature to 190 °C, both for ITO and InOx. AFM surface topography and SEM micrographs of the deposited films are consistent with the structural properties suggested by X-ray spectra: as the deposition temperature increases, the surface changes from a finely grained structure to a material with a larger-sized grain or/and agglomerate structure of the order of 250-300 nm. The roughness Rq varies from 0.74 nm for the amorphous tissue to a maximum of 10.83 nm for the sample with the biggest crystalline grains. Raman spectra are also presented.

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. 

Dielectric and Tunable Properties of Lead Barium Strontium Titanate Thin Films Fabricated by Radio Frequency Magnetron Sputtering Method

2013 ◽  
Vol 652-654 ◽  
pp. 1728-1732
Author(s):  
Zhi Meng Luo ◽  
Xiao Hua Sun ◽  
Shuang Hou ◽  
Ying Yang ◽  
Jun Zou
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Dielectric Loss ◽  
Magnetron Sputtering ◽  
Radio Frequency ◽  
Deposition Temperature ◽  
Room Temperature ◽  
Rf Magnetron Sputtering ◽  
Si Substrates ◽  
Tunable Properties

The Pb0.25Ba0.15Sr0.6TiO3 (PBST) thin films have been deposited on Pt/Ti/SiO2/Si substrates at different temperatures by radio frequency (rf) magnetron sputtering method. The microstructure, surface morphology, dielectric and tunable properties of PBST thin films were investigated as a function of deposition temperature. It’s found that the orientation of PBST thin films was adjusted by deposition temperature. The PBST thin film deposited at room temperature shows (100) preferred orientation and its dielectric constant and tunability are higher than that of PBST thin film deposited at 450 °C. Furthermore, the PBST thin film deposited at room temperature shows lower dielectric loss and leakage current, which makes it exhibit higher FOM of 49.47 for its appropriate tunability of 44.38% and low dielectric loss of 0.00897.

Studies on Water in the Hydration Chamber of a Modified Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 544-545
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
Steady State ◽  
Room Temperature ◽  
Small Mass ◽  
Equilibrium Pressure ◽  
Biological Objects ◽  
Mechanical Pump ◽  
Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

scholarly journals Titanium Nitride Thin Film Based Low-Redox-Interference Potentiometric pH Sensing Electrodes

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 42
Author(s):  
Shimrith Paul Shylendra ◽  
Wade Lonsdale ◽  
Magdalena Wajrak ◽  
Mohammad Nur-E-Alam ◽  
Kamal Alameh
Keyword(s):  
Thin Film ◽  
Titanium Nitride ◽  
Orange Juice ◽  
Ph Sensor ◽  
Reference Electrode ◽  
Cost Effective ◽  
Ph Sensing ◽  
Ph Sensors ◽  
Potential Shift ◽  
Double Junction

In this work, a solid-state potentiometric pH sensor is designed by incorporating a thin film of Radio Frequency Magnetron Sputtered (RFMS) Titanium Nitride (TiN) working electrode and a commercial Ag|AgCl|KCl double junction reference electrode. The sensor shows a linear pH slope of −59.1 mV/pH, R2 = 0.9997, a hysteresis as low as 1.2 mV, and drift below 3.9 mV/h. In addition, the redox interference performance of TiN electrodes is compared with that of Iridium Oxide (IrO2) counterparts. Experimental results show −32 mV potential shift (E0 value) in 1 mM ascorbic acid (reducing agent) for TiN electrodes, and this is significantly lower than the −114 mV potential shift of IrO2 electrodes with sub-Nernstian sensitivity. These results are most encouraging and pave the way towards the development of miniaturized, cost-effective, and robust pH sensors for difficult matrices, such as wine and fresh orange juice.

scholarly journals Direct measurement of the thermoelectric properties of electrochemically deposited Bi2Te3 thin films

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jose Recatala-Gomez ◽  
Pawan Kumar ◽  
Ady Suwardi ◽  
Anas Abutaha ◽  
Iris Nandhakumar ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermoelectric Properties ◽  
Bismuth Telluride ◽  
Indium Tin Oxide ◽  
Seed Layer ◽  
Room Temperature ◽  
Low Cost ◽  
Temperature Dependent ◽  
Temperature Heat ◽  
Electrochemically Deposited

Abstract The best known thermoelectric material for near room temperature heat-to-electricity conversion is bismuth telluride. Amongst the possible fabrication techniques, electrodeposition has attracted attention due to its simplicity and low cost. However, the measurement of the thermoelectric properties of electrodeposited films is challenging because of the conducting seed layer underneath the film. Here, we develop a method to directly measure the thermoelectric properties of electrodeposited bismuth telluride thin films, grown on indium tin oxide. Using this technique, the temperature dependent thermoelectric properties (Seebeck coefficient and electrical conductivity) of electrodeposited thin films have been measured down to 100 K. A parallel resistor model is employed to discern the signal of the film from the signal of the seed layer and the data are carefully analysed and contextualized with literature. Our analysis demonstrates that the thermoelectric properties of electrodeposited films can be accurately evaluated without inflicting any damage to the films.

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