Abdulla Suhail

• phD
• Senior Lecturer at Dijlah University College

In this paper, we present the experimental evidence of chaos generation, modulation by means of opto electronic feedback of semiconductor laser. The output photo current of the pin photo diode is amplified and re-injected as a feedback to the semiconductor laser. The injected feedback photo current produce chaotic laser output, the chaos distributi...

The synthesis of CdS nanoparticles from the reaction of CdCl2 and the sulfur dissolved in oleylamine in 1:2 mole ratio was used in the preparation of CdS nanocrystalline. The generation of white light from CdS nanoparticles (NPs) illuminated by UV−LED is presented. The PMMA fi lm doped with CdS nanoparticles was prepared. The generation of white lig...

In this work, the preparation of cadmium telluride (CdTe) nanoparticles by aqueous solution method is presented. The preparation process was performed in the presence of an acidic agent (L-cys) at certain pH value. The x-ray diffraction (XRD) patterns and scanning electron microscopy (SEM) of the prepared samples showed that poly crystalline struct...

In this work, the preparation of cadmium telluride (CdTe) nanoparticles by aqueous solution method is presented. The preparation process was performed in the presence of an acidic agent (L-cys) at certain pH value. The x-ray diffraction (XRD) patterns and scanning electron microscopy (SEM) of the prepared samples showed that poly crystalline struct...

it describe the detectivity and the number of sensors required for the thermal camera

Carbon nanotubes (MWCNTs,F-MWCNTs,SWCNTs) with different structure were fabricated into near-infrared photodetectors. Indium Tin Oxide (ITO) was used as a substrate to deposit CNTs by the drop casting method. The CNTs carrier concentrations, conductivity and carrier mobility were measured. Different types CNTs photodetectors exhibit a good photocon...

Carbon nanotubes (MWCNTs,F-MWCNTs,SWCNTs) with different structure were fabricated into near-infrared photodetectors. Indium Tin Oxide (ITO) was used as a substrate to deposit CNTs by the drop casting method. The CNTs carrier concentrations, conductivity and carrier mobility were measured. Different types CNTs photodetectors exhibit a good photocon...

In this work, ZnO quantum dots (Q.dots) and nanorods were prepared. ZnO quantum dots were prepared by self-assembly method of zinc acetate solution with KOH solution, while ZnO nanorods were prepared by hydrothermal method of zinc nitrate hexahydrate Zn (NO3)2.6H2O with hexamethy lenetetramin (HMT) C6H12N4. The optical , structural and spectroscopi...

The ZnO organic hybrid junction (electroluminescence EL device) was fabricated using phase segregation method. ZnO-nanoparticle (NPs) was prepared as a colloidal by self–assembly method of Zinc acetate solution with KOH solution. Nanoparticle is employed to form organic-inorganic hybrid film and generate white light emission, while N,N’–diphenyl-N,...

Far infrared photoconductive detectors based on multi-wall carbon nanotubes (MWCNTs) were fabricated and their characteristics were tested. MWCNTs films deposited on porous silicon (PSi) nanosurface by dip and drop coating techniques. Two types of deposited methods were used; dip coating sand drop –by-drop methods. As well as two types of detector...

SnO 2 UV photoconductive detector was fabricated. The Tin Oxide nanopowder have been prepared by sol gel chemical method and deposited on porous silicon by dipping coating technique. The structural, morphological, optical properties and electrical properties of the prepared SnO 2 nanopowder are studied. The X-ray analysis shows that the obtained po...

Zinc Oxide (ZnO) /porous-silicon photovoltaic device was fabricated to detect fast ultraviolet (UV) radiation pulses. The photovoltaic UV detector, based on the deposition of the ZnO wide-band gap semiconductor material on nanospikes silicon layer to form a heterojunction, has fast response time to the UV pulses. The current voltage characteristic,...

The silver nanoparticles (Ag-NPs) have been prepared using the electrochemical technique. The experimental setup of this technique consist of two electrodes of pure silver (99.2 %) , the applied voltage on the electrodes is 20 V and the current through the colloidal was about 0.4 Amp. The structure properties of the prepared nano-particles was carr...

The silver nanoparticles (Ag-NPs) have been prepared using the electrochemical technique. The experimental setup of this technique consist of two electrodes of pure silver (99.2 %) , the applied voltage on the electrodes is 20 V and the current through the colloidal was about 0.4 Amp. The structure properties of the prepared nano-particles was carr...

Fast response time IR photoconductive detector was fabricated based on Multi-Walled Carbon nanotubes (MWCNTs) film deposited by dip coating technique. The MWCNTs film is deposited on the porous silicon (PS) nanosurface which has drastically reduced the response time of the MWCNTs IR detector to few hundreds of microseconds. The surface functionaliz...

The composite CdSe/ZnS core – shell mixed with pyrene molecules in polymethyl meth-acrylate (PMMA) polymer was used to generate intense white light when illuminated by InGaN/GaN UV LED. The addition of pyrene molecules in low concentration to the core – shell system tuned the chromaticity coordinates to (0.25, 0.34) and increased the intensity of t...

A P-type Zinc Oxide (ZnO) /porous-silicon photovoltaic device was fabricated to detect fast ultraviolet (UV) radiation pulses. The photovoltaic UV detector, based on the deposition of the ZnO wide-band gap semiconductor material on nanospikes silicon layer to form a heterojunction, has fast response time to the UV pulses. The current-voltage charac...

The conversion efficiency of Si solar cell of 500m thickness was improved by etched the front solar surface using the photochemical etching technique. The etched surface was coated by a nanolayer of CdS nanoparticles of 4-8nm dimension. The CdS nanolayer was passivated with polyamide nylon. This treatment was highly improving the response of the so...

Fast response time UV photoconductive detector was fabricated based on ZnO film prepared by thermal chemical spray pyrolysis technique. The ZnO nanofilms are grown on the porous silicon (PS) nanosurface which has drastically reduced the response time of the ZnO UV detector from few seconds to few hundreds of microseconds. The surface functionalizat...

The work concentrate on the improvement of the ZnO photoconductive detector in the UV region. The improvement is based on two mechanisms : The first is the functionlization of the detector surface by specific polymer material and the second mechanism is to improve the structure of the film on the silicon layer through developing the porous layer on...

The conversion efficiency of Si solar cell of 500m thickness was improved by etched the front solar surface using the photochemical etching technique. The etched surface was coated by a nanolayer of CdS nanoparticles of 4-8nm dimension. The CdS nanolayer was passivated with polyamide nylon. This treatment was highly improving the response of the so...

The three-photon absorption (3PA) in nanostructure wide-band gap ZnO semiconductor material is observed under high intensity femtosecond Titanium-Sapphire laser of 800 nm wavelength excitation. The ZnO film was prepared by chemical spray pyrolysis technique with substrate temperature of 400˚C. The optical properties concerning the absorp-tion, tran...

Fast response time UV photoconductive detector was fabricated based on ZnO film prepared by thermal chemical spray pyrolysis technique. The ZnO nanofilms are grown on the porous silicon (PS) nanosurface which has drastically reduced the response time of the ZnO UV detector from few seconds to few hundreds of microseconds. The surface functionalizat...

The synthesis techniques of highly luminescent CdSe/ZnS core-shell composite nanocrystals are reported. The color-conversion, incorporating the photoluminescence emission of CdSe/ZnS core-shell nanocrystals in blue λ=350 nm and green λ=520 nm on near UV-InGaN/GaN LED λ=365 nm, was studied. The generated white light resulting from color-mixing of th...

The three-photon absorption (3PA) in nanostructure wide-band gap ZnO semiconductor material is observed under high intensity femtosecond Titanium-Sapphire laser of 800 nm wavelength excitation. The ZnO nanofilms were prepared by chemical spray pyrolysis technique with substrate temperature of 370 oC. The optical properties concerning the absorption...

Strong nonlinear absorption in CdS nanoparticles of dimensions in the range 4 -50 nm when irradiated with a femtosecond pulsed laser at 800 nm is observed. The CdS nanoparticles sizes were controlled by changing the reaction time of aqueous solutions of thiourea and cadmium chloride. The structure of the prepared CdS nanoparticles were tested and t...

The synthesis techniques of highly luminescent CdSe/ZnS core-shell composite nanocrystals are reported. The colour conversion, incorporating the photoluminescence emission of CdSe/ZnS core-shell nanocrystals in blue λ=410 nm, green λ=520 nm and red λ=620 nm on near UV-InGaN/GaN LED λ=365 nm, was studied. The generated white light resulting from col...

Palladium – doped ZnO thin film was deposited by chemical spray pyrolysis on glass substrate to be a fast hydrogen gas sensor. The prepared ZnO films were doped by dipping in palladium chloride PdCl2 dissolved in ethanol C2H5OH. The optical properties and the surface morphology of the prepared films were studied. The sensitivity and response time b...

Strong nonlinear absorption in CdS nanoparticles of dimensions in the range 4 - 50 nm when irradiated with a femtosecond pulsed laser at 800 nm is observed. The CdS nanoparticles sizes were controlled by changing the reaction time of aqueous solutions of thiourea and cadmium chloride. The structure of the prepared CdS nanoparticles were tested and...

Fast response time UV photoconductive detector was fabricated based on ZnO film prepared by thermal chemical spray pyrolysis technique. The ZnO nanofilms are grown on the porous silicon (PS) nanosurface which has drastically reduced the response time of the ZnO UV detector from few seconds to few hundreds of microseconds. The surface functionalizat...

The generation of white light from CdS nanoparticles (NPs) illuminated by UV-LED is presented. The synthesis of CdS nanoparticles from the reaction of CdCl2 and the sulfur dissolved in oleylamine in 1:2 mole ratio was used in the preparation of CdS nanocrystalline. The PMMA film doped with CdS nanoparticles was prepared. The generation of white lig...

A continuous wave semiconductor laser at 1310 nm was operated and used as a transmitter in an optical communication system. The output optical power of the laser diode was detected by a photo detector, and then re-injected inside the laser diode cavity, as an optoelectronic retarded feedback; this is to produce a perturbation inside it to achieve a...

The UV solar blind photoconductive detector was fabricated using ZnO film prepared by thermal chemical spray pyrolysis technique. The ZnO thin film was grown on quartz substrate heated to 400 ºC. The studies of the films structure and optical properties showed that the films are n-type with optical band gap of around 3.1-3.3 eV .The aluminum Interd...

The three-photon absorption in nanostructure wide-band ZnO semiconductor material is observed under lowintensity nanosecond Nd-YAG laser of 1.06 μm wavelength excitation. The measured nonlinear absorptioncoefficient was 0.058cm3/Gwatt2 which is about two order of magnitude higher than its value in solid. TheZ-scan measurements show that the thresho...

In this work, we are studying the electrical properties of pure liquid crystals and liquid crystals (LC) doped with carbon nanotubes (CNT). The p-methoxy benzalidineazobenzene liquid crystals doped with different concentrations (0.01, 0.05, 0.1) of CNT, are used the C-V characterization of the liquid crystals. the voltage- capacitance was studied f...

In this paper, Cu2S/CdS solar cells were prepared with different thickness of CdS layer, these layers were prepared by using chemical spray pyrolysis technique. The chemical spray solution was prepared by mixing cadmium chloride CdCl2 and thiourea CS(NH2)2 of molar concentration 0.1 M/L, the CdS layer was formed after the solution was sprayed on ho...

A high power, far infra-red laser, pumped by a long pulse high energy CO2 laser, has been developed to produce 8 μs pulses at 447 μm. The influence of the molecular weight of the far infra-red gas on the absorption of the pump energy is discussed. The results show that the heavy molecules are most convenient for long pulse far infra-red lasers.

The theoretical analysis and the experimental results show that the dependence of the laser output energy on the electron concentration mainly depends on the mechanism of the electron reduction in the main discharge. The logarithmic increasing of the laser output energy with the increasing of the electron density (which was mentioned in the literat...

A pulsed cold-cathode glow-discharge electron beam gun emitting an electron-beam of 150 keV energy and 45 cm2 cross-sectional area has been used to pump a short pulse CO2 laser. A fast discharge capacitor bank was used to help make the design simpler than that employed in liquid coaxial lines. The system developed is capable of producing a CO2 lase...

Zinc Oxide (ZnO) UV detector thin films have been prepared on nanospikes silicon layer with different etching time by spray pyrolysis using 0.1 M aqueous solution of Zinc acetate. The Hall measurements for ZnO films grown on the porous silicon layer, show that they were oriented in the c – axis and it is found to be a p – type semiconductor. This b...

A photoconductive CdSe:Cu detector was prepared by vacuum evaporation of 1µm thickness CdSe film, followed by doping of a 5wt % of Cu using vacuum annealing technique at variable temperatures under an argon atmosphere. The best results were obtained at 350ºC.The detector was found sensitive to a wider spectral range (0.4-12µm) than the conventional...