Investigate the Reliable and Accurate Pattern Transfer of IDE Silver Electrode Coated with Zinc Oxide Microwire for Biosensor Application

2014 ◽  
Vol 925 ◽  
pp. 529-532
Author(s):  
R. Haarindra Prasad ◽  
Kai Long Foo ◽  
U. Hashim
Keyword(s):  
Zinc Oxide ◽  
Electronic Device ◽  
Uv Light ◽  
Sol Gel ◽  
Electrical Characterization ◽  
Pattern Transfer ◽  
Zno Films ◽  
Oxide Material ◽  
Chemical Route ◽  
Biosensor Application

This paper illustrate a facile route to fabricate and develop zinc oxide microwire which acts as transducer for biosensor application. Pattern transfer process is conducted on the wafer substrate by using conventional photolithography process to form IDE electrode. The substrate is coated with positive photo-resist (PR) and exposed for UV light for 10 seconds. After development, the unexposed area is etched by using hydrochloric acid, HCI. In this study, zinc oxide material have become a remarkable choice for bio-sensing development due to large band gap and tailor for bio-molecular application. Zinc oxide solution was prepared through chemical route, that is by using sol-gel method. The coated ZnO films were annealed in furnace at 500°C for 2 hours. ZnO seed solution undergoes hydrothermal growth to synthesize ZnO microwires. ithThe substrate used for this study is p-type silicon wafer which is oxidized. SiO2 layer is used because it acts as an insulator which is very essential for an electronic device to avoid electrical leakage and improve electron mobility. Further investigation of morphological and electrical characterization is conducted through SEM and I-V test .Average size diameter of Zno microwire is 0.45μm and exhibit 900μA of current at 5V.

On the UV-light-induced Desorption/Adsorption Mechanism of Atmospheric Species in Solution-processed Zinc Oxide Thin Films

MRS Advances ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 111-117
Author(s):  
José Bruno Cantuária ◽  
Giovani Gozzi ◽  
Lucas Fugikawa Santos
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Electrical Properties ◽  
Uv Light ◽  
Atmospheric Oxygen ◽  
Low Cost ◽  
Environmental Parameters ◽  
Zno Films ◽  
Desorption Rate ◽  
Transparent Semiconductor

AbstractZinc oxide (ZnO) is a n-type transparent semiconductor which can be processed by low cost techniques (such as spray-pyrolysis and spin-coating) and can be applied as the active layer of thin-films transistors (TFTs). The electrical properties of ZnO films are strongly affected when the device is exposed to room conditions and/or UV-light, suggesting possible applications as UV or/and gas sensors. Atmospheric oxygen molecules adsorbed on ZnO surface act as charge traps, decreasing the material conductivity. The incidence of UV-light causes an increase of the material conductivity due to the photogeneration of electron-hole pairs via direct band-to-band transitions (classic photoconductivity process) and due to the desorption of oxygen molecules, which presents a relatively slower response and is a less understood mechanism. In the current paper, we study the influence of environmental parameters, such as temperature, humidity and UV-light intensity, on the electrical properties of spin-coated ZnO thin films to understand the role of the desorption mechanism on the photoconductivity process. The analysis of the device current vs. time curves shows the existence of two light-induced desorption mechanisms: i) one which increases the electrical conductivity of the ZnO film (desorption-like process) and ii) a second one which decreases the conductivity (adsorption-like process). A Plackett-Burman design of experiment (DOE) was used to study the influence of characterization factors like UV intensity, temperature and humidity on electrical parameters obtained from the experimental curves. We observed that the desorption-like process is a first order mechanism, exhibiting desorption rate proportional to n(t), where n(t) represents the adsorbate concentration as a function of the time, whereas the adsorption-like mechanism exhibits a desorption rate proportional to the forth power of n(t).

scholarly journals Nanorod Arrays Enhanced UV Light Response of Mg-Doped ZnO Films

Symmetry ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1005
Author(s):  
Der-Yuh Lin ◽  
Hone-Zern Chen ◽  
Ming-Cheng Kao ◽  
San-Lin Young ◽  
Wen-Yi Sung
Keyword(s):  
Uv Light ◽  
Sol Gel ◽  
Light Response ◽  
Band Gap Energy ◽  
Zno Films ◽  
Silicon Substrates ◽  
Nanorod Arrays ◽  
Nanocrystalline Films ◽  
Uv Illumination ◽  
Surface Morphologies

Zn1−xMgxO (x = 0, 0.03, 0.05, and 0.07) nanocrystalline films were grown on silicon substrates using the sol–gel method. Furthermore, Zn1−xMgxO vertically aligned hexagonal symmetrical nanorods with six reflection symmetries were fabricated on pure ZnO-seeded layer n-type silicon substrates via a low-temperature hydrothermal method to enhance the ultraviolet (UV) light response. The crystal microstructures and surface morphologies of nanocrystalline films and nanorod arrays were determined by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). Transmission spectra showed that the increasing Mg content will increase the band gap energy from 3.28 to 3.46 eV. However, the current–voltage curves in the dark and under UV illumination showed that the UV response did not improve by the incorporation of magnesium. We changed the flat surface of films into symmetrical nanorod arrays and demonstrated they can significantly enhance the normalized photo-to-dark-current ratio up to ten times.

Fabrication and characterization of sol-gel-derived zinc oxide thin-film transistor

2010 ◽  
Vol 25 (4) ◽  
pp. 695-700 ◽  
Author(s):  
Young Hwan Hwang ◽  
Seok-Jun Seo ◽  
Byeong-Soo Bae
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Low Cost ◽  
Sol Gel ◽  
Solution Process ◽  
Precursor Solution ◽  
Solution Concentration ◽  
Oxide Thin Film ◽  
Zno Films ◽  
Electron Conduction

Thin-film transistors (TFTs) with zinc oxide channel layers were fabricated through a simple and low-cost solution process. Precursor solution concentration, annealing temperature, and the process were controlled for the purpose of improving the electrical properties of ZnO TFTs and analyzed in terms of microstructural scope. The fabricated ZnO films show preferential orientation of the (002) plane, which contributes to enhanced electron conduction and a dense surface. The results show that the TFT characteristics of the film are clearly affected by the microstructure. The optimized TFT operates in a depletion mode, shows n-type semiconductor behavior, and is highly transparent (>90%) within the visible light range. It exhibits a channel mobility of 9.4 cm2/V·s, a subthreshold slope of 3.3 V/decade, and an on-to-off current ratio greater than 105. In addition, the result of N2 annealing shows the possibility of improvement in electrical property of the ZnO TFTs.

Performance of Ultraviolet Photoconductive Sensor Based on Aluminium-Doped Zinc Oxide Nanorod-Nanoflake Network Thin Film Using Aluminium Contacts

2013 ◽  
Vol 832 ◽  
pp. 298-302 ◽  
Author(s):  
M.H. Mamat ◽  
Nor Diyana Md Sin ◽  
I. Saurdi ◽  
N.N. Hafizah ◽  
Mohd Firdaus Malek ◽  
...  
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Seed Layer ◽  
Uv Light ◽  
Sol Gel ◽  
Zno Nanorod ◽  
Immersion Method ◽  
Coated Glass Substrate ◽  
Sensor Applications ◽  
Doped Zno

In this research, we fabricated UV photoconductive sensor using aluminium (Al)-doped ZnO nanorod-nanoflake network thin film. These nanostructures were deposited on the seed-layer-coated glass substrate using sonicated sol-gel immersion method. By using Al contacts, it was found that the performance of the UV photoconductive sensor is very good. The responsivity of the device was 46.4 mA/W with sensitivity of 17.5 under 365-nm UV light (5 mW/cm2) at bias voltage of 10 V. Our study revealed that these nanostructures are very promising material for the UV photoconductive sensor applications.

NANOCRYSTALLINE ALUMINUM DOPED ZINC OXIDE COATED FIBER OPTIC FOR ULTRAVIOLET DETECTION

2013 ◽  
Vol 22 (03) ◽  
pp. 1350037 ◽  
Author(s):  
A. R. A. RASHID ◽  
P. S. MENON ◽  
S. SHAARI
Keyword(s):  
Refractive Index ◽  
Fiber Optic ◽  
Uv Light ◽  
Sol Gel ◽  
Hexagonal Wurtzite Structure ◽  
Zno Films ◽  
Coated Fiber ◽  
Aluminum Doped Zinc Oxide ◽  
Doped Zno

In this paper, we report the fabrication and characterization of an ultraviolet sensing by using Al -doped ZnO films coated on quartz slide and silica fiber optic. Undoped ZnO , 0.5, 1, 2 and 3 at.% of Al were prepared by sol–gel method with annealing temperature of 400°C for 1 h. The presence of spherical shaped nanoparticles and hexagonal (wurtzite) structure were detected for Al doped ZnO by using FESEM and XRD. The band gap values increased by adding Al due to the increment of carrier concentration. I–V curves reveal an ohmic line and improvement in electrical conductivity when the samples are illuminated by ultraviolet (UV) light with a wavelength of 365 nm. At 1 at.% of Al , the film have a larger increment in photocurrent response when illuminated with UV light compared to undoped ZnO and higher concentration (2 at.% and 3 at.%) of Al . For coated fiber optic, the fiber operates under leaky mode and the refractive index of ZnO is decreasing under UV radiation. There is a small drop in output intensity and increased abruptly which depends on the changes of ZnO refractive index. The thin films have a longer recovery time than response time.

Study the Optical Characteristic of ZnO Nanostructure through Annealing at Various Time Period

2013 ◽  
Vol 832 ◽  
pp. 68-72 ◽  
Author(s):  
R. Haarindra Prasad ◽  
U. Hashim ◽  
Kai Long Foo ◽  
Tijjani Adam ◽  
Mohd Shafiq
Keyword(s):  
Zinc Oxide ◽  
Annealing Time ◽  
Electrical Characteristic ◽  
Silicon Oxide ◽  
Sol Gel ◽  
Annealing Process ◽  
Morphological Observation ◽  
Precipitation Process ◽  
Oxide Material ◽  
Time Period

Main purpose of this research is to study the optical and electrical characteristic of zinc oxide material after undergoing annealing process at various time period. Hypothesis of this research have proved that the physical properties of zinc oxide material have changed by increasing time period for annealing process due to changes of optical and electrical characteristic of ZnO material. Morphological observation shows that, the transmittance properties of ZnO material on glass substrate varies after annealing at time period 5 hours compare to annealing time of 3 hours followed by annealing time of 1 hour. All the annealing process is conducted at temperature 200°C. Zinc oxide is synthesized through a facile method which is known as sol-gel method. Sol-gel solution is prepared based on mixture of zinc acetate dehydrate and stabilizer mono ethanolamine (MEA) with ratio 1:1 and the mixture solution is left for more than 24 hours for precipitation process to occur. The prepared solution is then coated with 3 layers on silicon oxide substrate and annealed at time period of 1 hour, 3 hours and 5 hours. The annealed samples with different period of time is further characterized through UV-Vis test and electrical test.

Fabrication and Characterization of IDE Based Sensor through Conventional Lithography Method

2013 ◽  
Vol 832 ◽  
pp. 517-521 ◽  
Author(s):  
R. Haarindra Prasad ◽  
U. Hashim ◽  
K.L. Foo ◽  
Tijjani Adam ◽  
Mohd Shafiq
Keyword(s):  
Zinc Oxide ◽  
Sol Gel ◽  
Small Scale ◽  
Oxide Material ◽  
Hydrothermal Route ◽  
Insulator Layer ◽  
Lithography Process ◽  
Sol Gel Process ◽  
Auto Cad

This paper mainly illustrate regarding the fabrication process of IDE based sensor for bio-molecular detection process. Material that is utilized in this process is zinc oxide due to bio-compability and elevated electrical characteristic. IDE mask is designed by using auto-cad software which tailors for detection of bio substance which is extremely small scale in size. Zinc Oxide material is also used due to presented of nanostructure that can be synthesized through hydrothermal route. Zinc oxide solution is prepared by series of sol-gel process and is coated on the SiO substrate which acts as insulator layer during the lithography process. IDE mask is patterned transfer on sample by using conventional lithography process which the parameters are critically adjusted to ensure that the pattern transfer process occur with minimal defects. The fabricated sensor will be further validated through electrical and morphological characteristic. Capacitance test and impedance test is taken with various pH solution to observe the response of the sensor with different pH values. Keywords: IDE sensor, bio-compability, Zinc Oxide, auto-cad software, sol-gel, SiO substrate, hydrothermal route

Aluminum-Doped Zinc Oxide as Transparent Electrode Materials

2011 ◽  
Vol 685 ◽  
pp. 6-12 ◽  
Author(s):  
Yu Long Zhang ◽  
Xian Peng Zhang ◽  
Rui Qin Tan ◽  
Ye Yang ◽  
Jun Hua Zhao ◽  
...  
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Magnetron Sputtering ◽  
Electrode Materials ◽  
Sol Gel ◽  
Argon Plasma ◽  
Transparent Electrode ◽  
Zno Thin Films ◽  
Zno Films ◽  
Doped Zno

Pristine and Al-doped zinc oxide nanopowders were synthesized via a surfactant-assisted complex sol-gel method, possessing a pure ZnO phase structure and controllable grain size which was characterized by X-ray diffraction and scanning electron microscopy. Using these nanopowders, the pristine and Al-doped ZnO magnetron sputtering targets were prepared following a mold-press, cold isostatical-press and schedule sintering temperature procedure. The relative density of these as-prepared targets was tested by Archimedes’ method on densitometer. All of the results were above 95 theory density percents, and the resistivity was tested on four-probe system at a magnitude of 10-2Ω cm. Related pristine ZnO thin films and Al-doped ZnO thin films were fabricated by magnetron sputtering method, respectively. The pristine and Al-doped ZnO films deposited on the quartz glass by dc sputtering owned a (002) orientation with a thickness of 350 nm at a deposition power of 100 W for two hours under an argon plasma. A good optical transparency above 80% and low resistivity of 1.60×10-3Ω cm were obtained with a deposition temperature of 573 K. The optical energy bandgap could be tailored by Al doping at 4 at.% Al.

Zinc Oxide Films and Nanowires Synthesized by Sol-Gel and Hydrothermal Methods and their Applications

2013 ◽  
Vol 815 ◽  
pp. 752-757
Author(s):  
Wei Wei ◽  
Chun Fu Zhang ◽  
Da Zheng Chen ◽  
Rui Gao ◽  
Zhi Zhe Wang
Keyword(s):  
Zinc Oxide ◽  
Solar Cell ◽  
Hydrothermal Method ◽  
Spin Coating ◽  
Sol Gel ◽  
Zno Films ◽  
Zinc Oxide Films ◽  
Coating Method ◽  
Different Characteristics ◽  
Hydrothermal Methods

In this paper, we studied the methods to synthesize good ZnO materials that can be applied in real environment. First we used spin coating method to form a layer of sol-gel driven ZnO, and then a hydrothermal method was used to synthesize nanowires of ZnO on the already obtained ZnO films. Some methods of test, including AFM and SEM, were performed to analyze the different characteristics of the material. Finally, their applications in the fields of TFT and solar cell were studied. We find that the ZnO films and nanowires are good in quality and their applications in TFT and solar cell are satisfactory.

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