Advanced Materials Research Vol. 832

Abstract: In this paper, we present the properties of I-doped CuI thin films at different concentration of iodine dopant (e.g. 10mg, 20mg, 30mg, 40mg and 100mg). The doping of CuI was done by using double furnace chemical vapor deposition (CVD) method. The effects of I-doped CuI to its surface morphology and electrical were studied. The effect of iodine doping to surface morphology was measured by field emission scanning electron microscopy (FESEM). The morphology of all thin films shows insignificance changes in grain size, grain boundaries and particle structure as the doping concentration varies. For the electrical properties, high current at constant voltage of-5V to 5V was obtained. The resistivity of 10^-1 was obtained for undoped CuI thin films. While, for the series of I-doped CuI thin films, the resistivity of 10^-2 was obtained. The excess of hole conductor in the I-doped CuI thin films enhances the electrical conductivity of the films.

Abstract: The effect of oxygen doping to the properties of CuI thin films was studied. The doping of oxygen to the CuI thin films was done by using single furnace chemical vapor deposition (CVD) method at different oxygen gas flow rate (e.g 10, 20, 30, 40 and 50 sccm). The CuI thin film was first deposited by using mister atomizer at constant CuI solution concentration of 0.05M. The surface morphology and electrical properties of O-doped CuI was studied. The field emission scanning electron microscopy (FESEM) was used to observe the morphology of O-doped CuI thin films. The FESEM images revealed that all the CuI thin films deposited were uniform with the existence of nanostructured CuI particle. The EDX measurement confirm the existence of Cu:I in the films and also the variation of oxygen ratio in the CuI thin films as the oxygen was introduced. The resistivity of 10¹ Ωcm to 10³ Ωcm at constant voltage of-5V to 5V was obtained for the O-doped CuI thin films.

Abstract: odine incorporation to amorphous carbon (a-C) thin films offers many advantages and a full understanding of the properties of iodine doped amorphous carbon (a-C:I) thin films which is necessary for applications like optoelectronics devices and photovoltaic solar cells. Iodine doped amorphous carbon thin films have been doped by thermal chemical vapour deposition (CVD) technique at different amount of iodine. The effects of iodine amount on the properties of a-C:I thin films have been investigated using standard measurement techniques and discussed. FESEM studies have been performed on the doped films for the surface morphology studies. Raman studies have been carried out on the doped samples for the chemical bonding of carbon atoms. The sp² and sp³ contents have found to be dependent on the amount of iodine. For evaluation of the electrical and optical properties of the doped films, the current-voltage (I-V) measurement and UV-Vis-NIR spectroscopy have been performed on the a-C:I thin films. It has been observed that the a-C:I thin films doped with 1g has higher electrical conductivity and lowest optical band gap.

Abstract: 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.

Abstract: The effect of deposition time on properties of ZnO nanostructured thin film was investigated. The ZnO thin films were deposited at various times from 15~75 minutes. The ZnO thin film at 60 min deposition time shows the highest current density and high conductivity with 2.15x10^-2 Scm^-1. The optical properties of ZnO thin films show high transmittance with >80% at 380 nm to 1200 nm. The thickness of ZnO thin film increases linearly with deposition time. The size of ZnO thin films increase as the deposition time increase. Based from fesem images, the ZnO nanocolumnar structure was formed at 15 to 60 minutes deposition time while at 75 minutes the sample formed nanoflakes structure.

Abstract: The effects of polyvinyl alcohol (PVA) loading in ZnO/SnO₂ sol-gel immersion method were investigated. The sensor characteristic of in ZnO/SnO₂ nanocube was also been tested. The images of sample were carrying out by field emission scanning electron microscopy (FESEM) (JEOL JSM 6700F). The optical properties were characterized using photoluminescent (PL). The thin films were characterized using two point current-voltage (I-V) measurement (Keithley 2400) for electrical properties. The sensor was characterized using I-V measurement in a humidity chamber (ESPEC SH-261) and the chamber has been set at room temperature at 25°C relative humidity (RH %) is varied in the range of 40% to 90 %RH. The FESEM indicate the agglomeration and porous increase as the insertion of PVA into in ZnO/SnO₂ nanocube (PVA-ZnO/SnO₂ nanocube) compare with the as prepared in ZnO/SnO₂ nanocube. PL measurement of PVA-ZnO/SnO₂ nanocube describe blue shift behaviour after mixed the PVA. The sensitivity of the sensor of PVA-ZnO/SnO₂ nanocube and ZnO/SnO₂ nanocube were ratio of current 3.24 times and 12.7 times. While the response and recovery times of PVA-ZnO/SnO₂ nanocube higher response and recovery times as compare with ZnO/SnO₂ nanocube.

Abstract: A simple and cost effective method using a thermal oxidation process for synthesizing cupric oxide (CuO) nanostructures is demonstrated in this paper. Using elevated temperatures ranging from 100°C to 400°C, the optimum formation of CuO composition indicated by an X-ray diffraction (XRD) was obtained at 400°C. Then, the effects of gas flow rates (ranging from 1 to 10 kPa) on the formation of CuO nanorods were investigated using a field emission scanning electron microscope (FESEM). It was found that at higher gas flow rate, the formation of CuO nanorods was obviously observed. The current-voltage (I-V) characteristic obtained from an I-V measurement system shows that diode characteristic has been formed with threshold voltage (V_th) of 0.9 V and breakdown voltage (V_B) of-5 V. The mechanism of structural changes will be discussed in details.

Abstract: Zinc oxide (ZnO) is a promising electronic material for a variety of large area electronic applications including thin-film sensors, transistors, and solar cells. Various techniques have been focused and explored to synthesize ZnO films. In this study, sol-gel process was adopted as the fabrications process to grow the ZnO films. Three different types of solvents were used including ethanol, isopropanol and ethylene glycol as the reaction medium in the ZnO solution. The correlation between different solvents used and the properties of the ZnO films was explored and observed. The surface morphologies, structural and optical properties were examined using field émission scanning electron microscope (FESEM), X-ray diffractometer (XRD) and ultraviolet-visible (UV-Vis) spectroscopy. Through the observation from FESEM results, the surface morphology changed when different solvents were used. The crystallographic structures of the ZnO films demonstrate high crystallinity, and the extracted crystallite size is around 30 nm. Furthermore, ZnO films synthesized using isopropanol and ethylene glycol exhibit high transmittance spectra greater than 80% in the visible region. In general, the experimental results revealed that different solvents in the sol-gel process exert influences on the properties of the ZnO films.

Abstract: This paper focused on studying the effect of addition of Al₂O₃ , TiO₂ and BN nanofillers on dielectric strength of nanocomposite material. There are two types of polymer blends used in this project which are silicone rubber/EPDM and PP/EPDM blends. Nanocomposites samples was blended at 50:50 ratios and developed by compounding with and without 5 wt% concentration of Al₂O₃, TiO₂, and BN. The results are compared based on performance in dielectric properties of each types of polymer blends. From the weibull probability plot, PP/EPDM blend with nanofillers shows the higher dielectic strength compared to the SiR/EPDM blends. From the average value of electric field strength, it was found that the value of electric field strengths for PP/EPDM/Al₂O_3, PP/EPDM, PP/EPDM/TiO₂ and PP/EPDM/BN were 42.76kV/mm, 38.44 kV/mm and 32.93 kV/mm respectively. The results for SiR/EPDM with addition of Al₂O₃ , TiO₂ and BN are 37.43kV/mm 34.04kV/mm and 29.73kV/mm respectively. It was found that PP/EPDM blend gives better results for dielectric properties compared to SiR/EPDM blend.

Abstract: Pulp from the oil palm empty fruit bunches (EFB) was extracted via Alkaline Peroxide Pulping (APP). The pulping process was conducted through three main steps; dewaxing of EFB, impregnation of alkaline peroxide (AP) into EFB and refining of biomass to finally produce the pulp. The varying peroxide levels and number of impregnation stages were found to affect the refining energy consumption and the properties of the resultant pulp and paper. Diagnosis by electron microscopic imaging revealed a strong correlation between paper properties development and paper surface morphologies. By multiplying the stages of the low alkaline peroxide level (2:2.5% AP) impregnation, refining energy could be reduced by 30% while improving brightness and paper mechanical properties. Higher alkaline peroxide level (4:5% AP) could reduce the refining energy by 50% while still improving brightness. Beyond these AP levels (8:10% AP), refining energy could be reduced by 67% by increasing the number of impregnation stages, with positive effects on brightness and paper mechanical properties. The findings suggest that increasing the AP impregnation stages had exposed more active sites to react with AP. The enhanced AP accessibility to EFB structures facilitated mechanical fibrillation of EFB vascular bundles through the refining process. The proper synergy between AP and the adopted mechanical refining was the factor that triggered the liberation of nanocells from EFB biomass and this had ultimately improved paper properties.