Surface plasmon resonance could increase the efficiency of solar cells , when light is trapped by the noble metallic nanoparticles arrangement at and into the silicon solar cell (SSC) surface. Pure noble metal (silver and gold) nanoparticles (NPs) have been synthesized as colloids in de-ionized water (DW) by pulsed laser ablation (PLA) process at optimum laser fluence. Silicon solar cell with low efficiency was converted to plasmonic silicon solar cell by overcasting deposition method of silver nanoparticles on the front side of the SSC. The performance of plasmonic solar cell (PSC) was increased due to light trapping. Two mechanisms were involved : inserting silver nanoparticles (Ag NPs) inside the silicon layer by the heating effect of pulsed laser and depositing gold nanoparticles (Au NPs) on the surface of the SSC by overcasting method. The optical properties of silver and gold colloidal solutions were studied with UV- Visible spectrophotometer with a range from 190 nm to 1100 nm. The absorption spectra showed single absorption peak located at about the characteristic value for silver and gold nanoparticles due to the surface plasmon resonance. Atomic Force Microscope (AFM) images were studied , the ablated noble NPs by pulsed laser have an average diameter less than 100 nm. AFM images showed the morphology of SSC surface without and with nanoparticles before and after overcasting and heating by laser methods. Electrical measurements for SSC namely current – voltage ( I-V )characteristics and responsivity (Rλ) displayed higher efficiency after these procedures. The efficiency rise to(5.2%) due to the localized surface plasmons excitation of (Ag NPs) that were embedded into the silicon layer by the heating effect of pulsed laser. The deposition of AuNPs on the silicon surface of the plasmonic SC additionally increased the efficiency to (7.28%), due to light trapping by scattering from Au NPs towards the plasmonic solar cell depth .
A synthesis series of new heterocyclic derivatives (A2-A7) (pyrrole, pyridazine, oxazine and imidazol) derived from 4-acetyl-2,5-dichloro-1-(3,5-dinitrophenyl)-1H-pyrrole-3-carboxylate(A1) have been synthesised. Synthesis of compound (A2) by the reaction of starting material (A1) with hydroxyl amine hydrochloride in the presence of pyridine. Compound (A2) was reacted with hydrazine hydrate in dry benzene to give (A3) derivative. The compound )A3( deals with sodium nitrite to give diazonium salt, and the reaction diazonium salt with ethyl acetoacetate to produce compound (A4). To a mixture of compound (A4) and hydroxyl amine with sttired to yield (A5).Compound (A6) was prepared by reaction compound (A4) with thiosemicarbazide in presence
... Show MoreThe application of novel core-shell nanostructure composed of Cu, Ag, Au/NiO to improve the sensitivity of pure NiO to H2S gas sensors is demonstrated in this study. The growth of Cu, Ag, Au/NiO core-shell nanostructure is performed by chemical reaction of NiO on metal nanoparticle (Cu, Ag and Au) that prepared by pulsed laser ablation (PLA( technique. This is to form the homogeneous structure of the sensors investigated in this report to assess their sensitivity in terms of H2S detection. These novel H2S gas sensors were evaluated at operating temperatures of 25 °C, 100 °C and at 150 °C. The result reveals the Cu, Ag, Au/NiO core-shell nanostructure present a good sensitivity at low working temperatures compared by pure NiO nanoparti
... Show MoreAbstract: New copper(II) complexes with mixed ligand benziloxime (BOxH) and furfural-dehydeazine (FA) using classical (with and without solvent) and microwave heating methods have been prepared. The resulting complexes have been characterized using physico-chemical techniques. The study suggested that the ligands formed neutral complexes had general formulas [Cu(FA)(BOXH)(Ac)2] and [Cu(FA)(BOX)(OH)] in neutral (or acidic) and basic medium, respectively. Accordingly, hexa-coordinated mono-nuclear complexes have been investigated by this study and having distorted octahedral geometry. The effect of laser have been studied on solid ligands and solid complexes, no effect have been observed on most compounds through the results of melting poin
... Show MorePulsed laser deposition (PLD) technique was applied to prepared Chromium oxide (Cr2O3) nanostructure doped with Titanium oxide (TiO2) thin films at different concentration ratios 3,5,7 and 9 wt % of TiO2. The effect of TiO2 dopant on the average size of crystallite of the synthesized nanostructures was examined by X-ray diffraction. The morphological properties were discussed using atomic force microscopy(AFM). Observed optical band gap value ranged from 2.68 eV to 2.55 eV by ultraviolet visible(UV-Vis.) absorption spectroscopy with longer wave length shifted in comparison with that of the bulk Cr2O3 ~3eV. This indicated that the synthesized samples a
... Show MoreThis research dedicated to make an investigation for the variation of electron density concentration of D- region(NmD), at a characteristic height of 81 km throughout solar cycle 23, with solar activity(represented by sunspot number indices: international sunspot number(Ri), Northern hemisphere sunspot number(Rn) and Southern hemisphere sunspot number(Rs), as well as, the correlation between these indices for Baghdad city(lat.: 33.3o N, long.: 44.4o E) at local noon time during the ascending and the descending phases of solar cycle 23. A very strong directly relationship were found between Ri, Rn and Rs with NmD, as well as, the correlation coefficient between these parameters have been calculated and it has been found it is equal, i.e.,
... Show MoreThis work study the effect of laser surface heat treatment on physical properties (green density, density after sintering, theoretical density and porosity)of a composite material of an Al powder as a matrix with different percentage of B4C powder as additive material. This work was done by two stages: First stage: Production the maincomposite material which is contain Al powder with grain size 24μm as a matrix and B4C powder with grain size 50μm as additive with different weight percentage (5%,10%,15%,20%,25%,30%), and the powders Maxined for suitable time 15min, after that the mixture compacted with 2ton and sintered at 550C0. Second stage: Laser surface treatment was done for the productive composite material after sintering by usin
... Show MoreBackground: one of the complications of power bleaching is surface roughness of enamel which increases the possibility of post bleaching teeth discoloration. The aim of the present study is to evaluate the effect of toothpaste containing nano hydroxyapatite, NovaMin and kin sense fluoride on surface roughness of human tooth enamel after laser bleaching with 35% hydrogen peroxide bleaching gel. Materials and Methods: Twenty human enamel incisors were cleaned and their labial surface polished up to #1200, then categorized into four equal groups; first group kept without bleaching as a control group, while the remaining three experimental groups were bleached with 35% hydrogen peroxide, and each group treated with a restore paste containing o
... Show MoreIn this research study the effect of irradiation by (CW) CO2 laser on some optical properties of (Cds) doping by Ni thin films of (1)µm thickness has been prepared by heat evaporation method. (X-Ray) diffraction technique showed the prepared films before and after irradiation are ploy crystalline hexagonal structure, optical properties were include recording of absorbance spectra for prepared films in the range of (400-1000) nm wave lengths, the absorption coefficient and the energy gap were calculated before and after irradiation, finally the irradiation affected (CdS) thin films by changing its color from the Transparent yellow to dark rough yellow and decrease the value absorption coefficient also increase the value of energy gap.