scispace - formally typeset
Search or ask a question
Author

M. Abdel Rafea

Bio: M. Abdel Rafea is an academic researcher from Islamic University. The author has contributed to research in topics: Thin film & Crystallite. The author has an hindex of 15, co-authored 29 publications receiving 556 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: In this paper, the authors used SILAR to deposit amorphous copper oxide films and found that the band gap for amorphou film was 2.3 and 2.4
Abstract: Amorphous copper oxide films were deposited using the SILAR technique. Both Cu2O and CuO crystallographic phases exist in deposited and annealed films. Crystallization and growth processes by annealing at temperatures up to 823 K form grains with nano- and micro-spherical shapes. The calculated crystallite size from the XRD measurement was found to be in the range 14–21 nm while nano-spheres in the diameter range 50–100 nm were observed by SEM micrographs. The band gap for amorphous film was found to be 2.3 eV which increased slowly to 2.4 eV by annealing the film at 373 K. This was explained by defect redistribution in amorphous films. Annealing in the temperature range 373–673 K decreased the band gap gradually to 1.85 eV. The decrease of the band gap with annealing temperature in the range 373–673 K agrees well with the Brus model of the energy gap confinement effect in nanostructured semiconducting materials. Annealing in the temperature range 673–823 K decreases the band gap slowly to 1.7 eV due to the smaller contribution of the confinement effect. Below 573 K, Cu2O is the most probable crystalline phase in the film, while Cu2O and CuO crystalline phases may coexist at annealing temperatures above 573 K due to further oxidation of Cu2O. A wider transmittance spectral window in the visible region was obtained by controlling the annealing conditions of the amorphous copper oxide film and its applicability to the window layer of solar cell was suggested.

142 citations

Journal ArticleDOI
TL;DR: In this paper, a stoichiometry Zn0.5Cd0S nano-structured powder was synthesized by dip-coating method onto glass substrates and the X-ray diffraction analysis of the prepared powder and films were performed to investigate the crystalline structure.

71 citations

Journal ArticleDOI
A.A.M. Farag1, A. M. Mansour, A.H. Ammar1, M. Abdel Rafea, A.M. Farid1 
TL;DR: In this paper, SCC thin films were successfully prepared, using dip coating technique, and thermal gravimetric analysis (TGA) was performed for studying the thermal stability of SCC film.

51 citations

Journal ArticleDOI
TL;DR: In this paper, the Stokes shift between absorption and emission of oxazine was analyzed and the analysis of the spectral behavior of the absorption coefficient (α) of OXZ, in the absorption region revealed a direct transition, and the energy gap was estimated as 1.82 eV.

46 citations

Journal ArticleDOI
TL;DR: In this article, the optical properties of polyaniline, PANI thin films of different thicknesses were characterized by using spectrophotometric measurements of transmittance and reflectance in the spectral range of 200-2500nm.

38 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: UV-Visible ار راد ن .د TiO2 ( تیفرظ راون مان هب نورتکلا یاراد لماش VB و ) رگید اب لاقتنا VB (CO2) .
Abstract: UV-Visible ار راد ن .د TiO2 ( تیفرظ راون مان هب نورتکلا یاراد یژرنا زارت لماش VB و ) رگید زارت ی یژرنا اب ( ییاناسر راون مان هب نورتکلا زا یلاخ و رتلااب VB یم ) .دشاب ت ود نیا نیب یژرنا توافت یژرنا فاکش زار ، پگ دناب هدیمان یم .دوش هک ینامز زا نورتکلا لاقتنا VB هب VB یم ماجنا دریگ ، TiO2 اب ودح یژرنا بذج د ev 2 / 3 ، نورتکلا تفج کی دیلوت یم هرفح .دیامن و نورتکلا هرفح ی نا اب هدش دیلوت یم کرتشم حطس هب لاقت ثعاب دناوت شنکاو ماجنا اه یی ددرگ . TiO2 دربراک ،دراد یدایز یاه هلمج زا یم ناوت اوه یگدولآ هیفصت یارب (CO2) و بآ و ... نآ زا هدافتسا درک .

2,055 citations

Journal ArticleDOI
TL;DR: Recent progress in synthesis, characterization, processing and application of polyaniline (PANI) with the focus on the period 2010-2012 is reviewed in this paper, where new insights in the mechanism of formation of molecular/supramolecular PANI structures are discussed.

627 citations

Journal ArticleDOI
TL;DR: P-type oxides still lag in performance behind their n-type counterparts, which have entered volume production in the display market, and recent successes along with the hurdles that stand in the way of commercial success of p-type oxide semiconductors are presented.
Abstract: The development of transparent p-type oxide semiconductors with good performance may be a true enabler for a variety of applications where transparency, power efficiency, and greater circuit complexity are needed. Such applications include transparent electronics, displays, sensors, photovoltaics, memristors, and electrochromics. Hence, here, recent developments in materials and devices based on p-type oxide semiconductors are reviewed, including ternary Cu-bearing oxides, binary copper oxides, tin monoxide, spinel oxides, and nickel oxides. The crystal and electronic structures of these materials are discussed, along with approaches to enhance valence-band dispersion to reduce effective mass and increase mobility. Strategies to reduce interfacial defects, off-state current, and material instability are suggested. Furthermore, it is shown that promising progress has been made in the performance of various types of devices based on p-type oxides. Several innovative approaches exist to fabricate transparent complementary metal oxide semiconductor (CMOS) devices, including novel device fabrication schemes and utilization of surface chemistry effects, resulting in good inverter gains. However, despite recent developments, p-type oxides still lag in performance behind their n-type counterparts, which have entered volume production in the display market. Recent successes along with the hurdles that stand in the way of commercial success of p-type oxide semiconductors are presented.

507 citations

Journal ArticleDOI
TL;DR: In this article, the main drawback of PANI is lack of solubility, which explains its limited processability due to a rigid backbone, and various procedures have been adapted to improve PANI's processability.

264 citations

Journal ArticleDOI
TL;DR: In this article, various morphologies of CuO/Cu(OH)2 nanostructures with different adsorbed -OH contents were synthesized on an acid-treated Cu foil through variation of NaOH concentration from 0 to 50 mM with an in situoxidation method.
Abstract: Various morphologies of CuO/Cu(OH)2 nanostructures with different adsorbed –OH contents were synthesized on an acid-treated Cu foil through variation of NaOH concentration from 0 to 50 mM with an in situoxidation method. X-ray diffractometry and X-ray photoelectron spectroscopy (XPS) indicated formation of CuO on the Cu(OH)2 crystalline phase at a growth temperature of 60 °C for 20 h. Antibacterial activity of the nanostructures against Escherichia coli bacteria was studied in the dark and under light irradiation. The nanostructures grown at a NaOH concentration of 30 mM showed the highest surface area and the strongest antibacterial activity among the samples. After elimination of the contribution of the effective surface area of the nanostructures to the antibacterial activity, it was found that the surface morphology and chemical composition of the nanostructures were the other most important parameters in the antibacterial activity of the nanostructures. Using XPS analysis, the better photocatalytic activity per surface area of the nanostructures prepared at higher NaOH concentrations was substantially attributed to the amount of adsorbed OH bonds on the surface of the nanostructures.

252 citations