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

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).

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Spin Speed and Duration Dependence of TiO2Thin Films pH Sensing Behavior

Journal of Sensors ◽

10.1155/2016/9746156 ◽

2016 ◽

Vol 2016 ◽

pp. 1-8 ◽

Cited By ~ 2

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.

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

Jurnal Teknologi ◽

10.11113/jt.v78.8770 ◽

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.

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Oxygen Plasma Functionalized Multiwalled Carbon Nanotube Thin Film as A pH Sensing Membrane of Extended-Gate Field-Effect Transistor

IEEE Electron Device Letters ◽

10.1109/led.2013.2278214 ◽

2013 ◽

Vol 34 (10) ◽

pp. 1307-1309 ◽

Cited By ~ 4

Author(s):

Wan-Lin Tsai ◽

Bai-Tao Huang ◽

Po-Yu Yang ◽

Kuang-Yu Wang ◽

Ching Hsiao ◽

...

Keyword(s):

Thin Film ◽

Carbon Nanotube ◽

Field Effect ◽

Oxygen Plasma ◽

Field Effect Transistor ◽

Multiwalled Carbon Nanotube ◽

Ph Sensing ◽

Multiwalled Carbon ◽

Effect Transistor ◽

Sensing Membrane

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Degradasi Gas Benzena Melalui Proses Pemangkinanfoto Saput Tipis TiO2

Jurnal Teknologi ◽

10.11113/jt.v34.640 ◽

2012 ◽

Author(s):

Wan Azelee Wan Abu Bakar ◽

Mohd Yusof Othman ◽

Noor Khaida Wati Mohd Saiyudi ◽

Keiichi Tanaka

Keyword(s):

Thin Film ◽

Light Source ◽

Tio2 Thin Film ◽

Uv Light ◽

Wave Length ◽

Sol Gel ◽

Dip Coating ◽

Optimum Ratio ◽

Coating Method ◽

Dip Coating Method

Pengoksidaanfoto benzena fasa gas menggunakan saput tipis TiO2 yang disinari lampu ultralembayung telah dikaji. Saput tipis ini disediakan melalui kaedah celup angkat menggunakan sol–gel TiO2. Tindak balas yang sama juga telah dijalankan menggunakan saput tipis TiO2 yang didop dengan Cu2+ dan Fe3+ dengan nisbah mol TiO2 terhadap ion logam 1:0.005, 1:0.001, 1:0.0005 dan 1:0.0003. Hasil kajian menunjukkan mangkin TiO2 dengan pancaran cahaya UV (354 nm) mendegradasikan gas benzena sebanyak 90% dalam masa 55 minit. Walau bagaimanapun penambahan ion Fe3+ dengan nisbah 1:0.0005 meningkatkan peratusan degradasi benzena kepada 98% dalam masa 55 minit, sebaliknya penambahan Cu2+memberikan kesan negatif kepada aktiviti foto TiO2. Kajian juga memperoleh satu nilai optimum dengan aktiviti pemangkinan adalah tertinggi bagi kedua-dua ion Fe3+ dan Cu2+. Pengaruh panjang gelombang cahaya ke atas aktiviti foto TiO2 juga telah dikaji dengan menggunakan mangkin TiO2 dop Fe3+ dengan nisbah optimum. Hasil kajian menunjukkan bahawa degradasi gas benzena meningkat dengan pengurangan tenaga cahaya yang dipancarkan. Kata kunci: Pemangkinanfoto; pengoksidaanfoto; saput tipis; TiO2 The gas phase photooxidation of benzene was investigated using TiO2 thin film irradiated with UV light source. The thin film was prepared via TiO2 sol gel dip coating method. The same reaction was also carried out using TiO2 doped with Cu2+ and Fe3+ with 1:0.005, 1:0.001, 1:0.0005 and 1:0.0003 mole ratios. The results showed that 90% of benzene was degraded after 55 minutes UV (354 nm) irradiation of the TiO2 thin film. However the addition of Fe3+ ions with 1:0.0005 mole ratio degraded 98% of benzene within 55 minutes. In contrast, Cu2+ ions however give a detrimental effect to the photoactivity of TiO2. An optimum ratio of dopant, where TiO2 showed the highest activity, was determined for both Fe3+ and Cu2+. The effect of different wave-length light source was also carried out using TiO2 doped Fe3+ with optimum ratio. The degradation of benzene was found to increase with decreasing light energy. Key words: Photocatalysis; photooxidation; TiO2 thin film

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