Papers by Author: Irma Hidayanti Halim Affendi

Abstract: Poly (2-methoxy-5(2’-ethylhexyloxy)-phenylene vinylene) (MEH-PPV) thin films were deposited by spin-coating technique. The MEH-PPV powders were dissolved in toluene solution. In this study, we report the effect of ageing on electrical and optical properties MEH-PPV thin films. The thickness of MEH-PPV increased as ageing time increased. The electrical properties were obtained using 2-point probe. The resistivity of thin films decreased as ageing time increased and vice versa with conductivity. The optical properties were investigated using UV-Visible-NIR (UV-VIS-NIR) and atom force microscope (AFM). From UV-Vis result shows the lower band gaps of films in toluene solution proved MEH-PPV has longer conjugation segments. The surface roughness of thin films decreased with the increased of ageing time; which is caused by the aggregation of the MEH-PPV. The PL spectra show the quenching of emission might be due to the conjugation of length polymer changes in different ageing times.

Abstract: The production of TiO₂ nanostructured thin film was synthesized by sol-gel method using TiO₂ nanopowder as precursor. The solution of TiO₂ was then deposited as thin film onto glass substrate by spin-coating technique. The aim is to investigate the effect of concentrations on the surface morphology and electrical properties of the thin films. The effect on the surface morphology was observed by Field Emission Scanning Electron Microscopy (FESEM) and Atomic Force Microscopy (AFM). The electrical properties were then observed by two-point probe method. By measuring the current-voltage (IV) characteristic, resistivity and conductivity can be measured. The purpose of this paper is to investigate the surface morphology and the IV characteristic of the thin films.

Abstract: Titanium Dioxide film will be deposited on a glass slide substrate by spin coating technique which is the frequently used technique because of its easy operation and cheap due to the sol gel preparation. The deposited films were then characterized by cross section technique using Field Emission Scanning Electron Microscopy (FESEM) to investigate the thickness based on the number of coatings. Then by the same FESEM, the surface morphology was studied to see the grain size and the porosity of each film based on the number of coatings. AFM was used to see the uniformity of the thin film's surface. Then by using current voltage (IV) measurement, the electrical property of the film can be studied, from IV characterization the resistivity of the film will be calculated. In this investigation, it is found that by increasing the coating layer, the resistivity values were decreasing whereas the conductivity of the film is increasing since conductivity is the inverse of resistivity. The porosity of the film also increases with the coating layers.