Azrif Manut

Effect of annealing temperature on electrical and optical properties of ZnO thin films prepared by sol gel method

In this work, ZnO thin films were deposited on glass substrates using spin coating method. Different annealing temperature from 400 to 550°C significantly distresses the nature of electrical and optical properties of ZnO thin films have been investigated. The effect of annealing temperature on optical and electrical properties of nanostuctured ZnO thin films deposited by spin coating method has been studied. The optical properties were characterized by ultraviolet visible (UV-VIS-NIR) spectrophotometer. The electrical properties were analyzed using I-V measurement (CEP 2000). Gold (Au) was used as a metal contact using electron beam thermal evaporator (ULVAC). The optical transmittance spectrums showed the average transmittance of ZnO thin film with different annealing temperature higher than 90% in visible wavelength region. The optical band properties of the nanostructured ZnO thin films were analyzed by UV Vis and Tauc method was accepted to estimate the optical gap and absorption coefficient. The resistivity of the film decreased as the annealing temperature increased from 400 to 550oC. The highest conductivity values of ZnO thin film was obtained at 500°C with value 0.000197 Scm-1. Moreover, the higher porosity was found at 400oC with value 57.5%. The higher porosity of ZnO thin film can be expected the high sensitivity for gas sensor due to the material has a comparatively large surface area.

Review on electroluminescence behaviour of organic light emitting diode

In this paper report a review on electroluminescent efficiency using a deoxyribonucleic acid (DNA) complex as an electron blocking layer (EBL) material in emitting organic light emitting diode (OLED). The resulting called BioLED showed a high luminous efficiency. The DNA-based BioLED was as much more efficient and brighter than their OLED counterparts. It is found the effect of EBL is to increase the device turn-on voltage for OLED structure. This is attributed to the fact that the DNA complex increases the series resistance of the device which is turn reduces the current through the device.

Characterization of Inter Digital capacitor for water level sensor

This paper discussed about design and characterization of the Inter Digital capacitor. The main objective is to study the effects of width and spacing of the capacitor electrode on capacitance value. Water levels sensors are studied by using Inter Digital Capacitor (IDC) technique on Printed Circuit Board (PCB). IDC technique is used to make the capacitance measurement of the solution became more effective. This paper also presents simulation and experimental data to characterize the sensor. The result shows that the capacitance value is directly proportional to the electrodes width and inversely proportional to the electrodes spacing.

Design, fabrication and characterization of pH transducer using printed circuit board (PCB)

This paper discussed about design, fabrication and characterization of pH transducer on printed circuit board (PCB). The main objective is to explore the possibility of pH transducer by using interdigital capacitor (IDC) on PCB and to study the performance of interdigital capacitor on PCB. The transducer can be used to sense the pH value for a solution. The term interdigital refers to pattern of fingers that is resembled by the shape and relative position of the electrodes. This transducer was fabricated by using PCB in order to prepared a lower cost pH transducer compared to the commercialize pH transducer. In addition, the result produces the capacitance changes over the time is 0.0189 µF/s. Moreover, the percentage of drift test is about 39.6% and the hysteresis is about 0.086µF and 0.895 µF. The results show that a good correlation coefficient was observed in sensitivity test. The correlation coefficient for sensitivity test is about 0.65. As long as the value of correlation coefficient is above 0.5 the transducer is good.

Electroluminescence behavior of MEH-PPV based organic light emitting diode

Electroluminescence behavior of Poly [2-methoxy-5-(2-ethylhexyloxy) -1,4-phenylenevinylene] (MEH-PPV) as the emissive layer has been investigated in organic light emitting diode (OLED). The typical structure of polymer light emitting diode (PLED) is gold (Au) / MEH-PPV / ITO (Indium Tin Oxide). In this study, we investigated the EL behavior of single layer MEH-PPV at various applied voltages from 1 V to 5 V. The absorbance of MEH-PPV thin film and the EL spectra from 400 nm to 800 nm wavelength of the MEH-PPV device were discussed. The turn-on voltage is almost 1 V and the result showed that higher intensity with 5 V turn-on voltages.

Effect of indium concentration on optical and electrical properties of in doped ZnO thin films for gas sensing application

The deposition of Indium doped ZnO thin films using sol gel spin coating technique will be discussed in this paper. The concentrations of indium doping of the thin films were varied from 1.0-5.0 at. % indium. The effect of various doping concentrations 1.0-5.0 at. % indium on electrical, optical properties and gas sensing application were studied. The electrical properties were analyzed using I-V measurement (CEP2400). The optical transmittance and optical band gap were characterized by ultraviolet visible (UVVIS) spectrophotometer. Gold (Au) was used as a metal contact using electron beam thermal evaporator (ULVAC). The optical result show that the indium doped ZnO thin films revealed higher than 90% of transmittance value. The highest electrical resistivity was found 1.95E+04 £lcm at. 2% indium concentration. The optimum result of Indium doped ZnO thin films will be used for gas sensing application and gas sensitivity of the thin films will be extensively discussed in this paper.

Radar measurements of small objects in UWB frequency range

This paper reports on experimental results of radar measurements of basic targets using Ultra Wide Band (UWB) signals. The measurement was conducted in a laboratory room using UWB signals with frequency up to 1 GHz bandwidth. Targets used in this experiment are flat square plate and a square cube made from aluminum plates. It was observed that improved resolution of 5° was obtained with UWB signal, compared to using continuous wave (CW). Up to 3 dB reduction of side lobe fluctuation was also observed in specific incident angle.

Implementation of multiple linear regressions in lubricant degradation prediction algorithm

This paper presents the development of the prediction algorithm of lubricant degradation based on Beer Lamberts transmittance theory by using Multiple Linear Regressions (MLR). Recently, an increasing amount of wasted lubricant has been due to the unnecessary changing of lubricant even though the lubricant still remains its lubrication behavior. Therefore, a condition based technique is introduced to monitor the degradation parameters in lubricating oil by using optical approach. This work focuses on Total Acid Number (TAN) that has been identified as the main parameter in determining the lifetime of lubricant and it occurred at band location from 1,050-1,250cm-1 and 1,700-1,730cm-1. The best input parameter has been identified for sensor development and signal processing. Then, the prediction model is used to validate the measured and the predicted value of degradation. The high correlation between the predicted and measured data shows the prediction algorithm can be used for prediction purposes efficiently.

Mechanical parameters characterization of planar FEF fingers for pH sensor

This paper presents a study of Planar Fringing Electric Field (FEF) as a pH sensor. Fringing Electric Field or FEF is widely used as a structure to detect capacitance in material under test (MUT). The study is carried out using Inter Digital Capacitor (IDC) technique on Printed Circuit Board (PCB). This study is to investigate the effectiveness of using IDC as to reduce the cost of making sensor. The study focused on the effect of using Ground, number, width and length of finger on the PCB. This paper also presents both simulation and experimental data to characterize the sensor.. The results show that the trend pattern of both simulation and experiment are similar and for the series IDC, the capacitance is decreasing as the number of series IDC increased.

Correlation study between doping technique towards diffusion rate and oxidation rate

This paper is to investigate correlation between doping technique towards diffusion rate and oxide growth rate. There are two types of doping technique that has been investigated such as Solid Source, SS and Spin on Dopant, SOD. Four inches wafers were used to investigate the effects of doping technique towards diffusion rate and oxidation rate. The resistivity of silicon substrate is measured by using 4-point probe while the oxide thickness is measured by an Ellipsometer. From this experiment, it can be concluded that diffusion rate of Solid Source is about 86% better than Spin on Dopand. While the oxide growth of Solid Source, SS is 3.6% better than Spin on Dopant.