This study aims to investigate the optoelectronic properties of Co3O4/ZnO/Si double heterojunctions. We investigated the effects of spray cycles and, consequently, the film thickness of Co3O4/ZnO/Si films prepared by Chemical Spray Pyrolysis CSP, while at 350° the substrate temperature was kept constant on the morphological, structural, optical and electrical properties of the films. Investigation the relationship between film thickness, crystallinity, surface morphology, phase stability, topography, and optical properties can provide valuable information for the development of Co3O4/ZnO/Si based devices for optoelectronic applications. The synthesis and characterization of highly oriented nanostructured ZnO thin films by CSP with using an aqueous zinc chloride solution were investigated. The effects of film thickness on the morphological, structural, optical and electrical properties of the films were investigated. X-ray diffraction analysis revealed that all films exhibited a polycrystalline hexagonal wurtzite ZnO structure with a preferential orientation in the (002) direction. As the film thickness increased from 200 nm to approximately 390 nm, the crystallite size increased from 8.97 to about 15.54 nm. However, no significant change in the crystal lattice constant was observed. The stoichiometry of the as-deposited films was determined by energy dispersive x-ray spectroscopy (EDS). Additionally, atomic force microscopy (AFM) was utilized to measure the roughness RMS value, which demonstrated an improvement in surface roughness with increasing film thickness. The optical energy gap decreased from 3.1 eV to 2.8 eV with increasing film thickness. According to the results, the higher thickness films are superior to the thinner ones in terms of crystallinity quality and electrical properties. The nanostructured Co3O4 thin film was prepared on glass and silicon substrates by CSP using CoCl2 solution. The impacts of film thickness on the characteristics of the films were investigated. XRD results indicated that all films have a polycrystalline cubic phase structure with a preferential orientation in the (111) direction. As the film thickness increased, the crystallite size also increased, the crystallite size increased from 205 nm to about 439 nm, but no significant change in lattice constants were observed. The films developed two absorption edges, with the energy gap decreasing with increasing film thickness from 2.1 eV to 1.9 eV and from 1.49 eV to 1.47 eV. The Co3O4/ZnO/Si double heterojunctions were fabricated with different layer configurations on glass and silicon substrates. Morphological analysis reveals variations in nanorod orientation, packing density, and porosity with average grain sizes of about 100 nm. Based on the optical properties, triple energy bandgap regions were observed. ZnO shows an energy bandgap from 2.35 eV to 3.15 eV, while Co3O4 shows energy bandgaps from 1.85 eV to 2.23 eV and 1.35 eV to 1.5 eV. The responsivity measurements show that the Co3O4/ZnO/Si double heterojunction exhibits the highest responsivity over a wide range of wavelengths, with distinct peaks at 480 nm and 950 nm. This indicates that the photodetector is capable of detecting both visible and infrared light. These results provide valuable insights into the optimization of Co3O4/ZnO/Si double heterojunctions for broadband, high-performance photodetection applications.

A two-step unique approach is used to create purified as well as ligand-free gold quantum dots as a novel kind of fluorescence material. Noble Au targets are submerged in benzene solvent to evaluate the impact of changes in laser energy as well as the impact of laser re-irradiation on Au quantum size. Three samples of gold quantum dots AuQDs are prepared by pulsed laser ablation in benzene solvent at pulse fluencies of 4, 8, and 12 J/cm2, which are referred to as F1, F2, and F3, respectively. In addition, Syntheses three samples of GQDs (S1, S2 and S3) are carried out by laser ablation and re-irradiation of Au target in Benzene. Nd:YAG laser was utilized in the current experimentation with laser energy density of about 12 J/cm2, a wavelength of 1064 nm with 1000 laser pulses (S1). Then, the wavelength of 532nm with two different pulses repetition of 1000 (S2) and 2000 pulses (S3) was utilized as re-irradiation to reduce size. The prepared AuQDs got defined using UV-Vis, HR-TEM, XRD, XPS, EDX, FTIR, Raman spectroscopy and Photoluminescence measurement. AuQDs that were synthesized have monocrystalline and cubic (FCC) structure, according to XRD patterns. It was found out that the direct optical energy gap of AuQDs is enhanced to 2.35 , 2.5 and 2.6 eV. The emission photoluminescence emission spectra is at roughly 481, 445, and 437 nm, for F1, F2, F3 samples, respectively. The quantum size was reduced to 3.5 nm for sample F3. This strategy has the ability to prepare pure AuQDs in one step .On the other hand, the UV-visible spectra for re-irradiated GQDs produced at three distinct samples S1, S2 and S3, reveal a UV peaks at 311 nm, 309 nm, and 307 nm, respectively. The optical energy gap values of GQDs were shown to be within the range of 2.5, 2.7 and 2.8 eV of samples S1, S2 and S3, respectively. The Photoluminescence emission spectra maximum peak heights were observed at about 445, 432, and 405 nm for the specimens S1, S2 plus S3, correspondingly. In contrast to the control specimen (S1), the data obtained demonstrate that the re-irradiated quantum dots in Benzene (S3) have blue shift and higher Photoluminescence and the sizes of quantum dots are less than 2 nm for S3. That results promising biosensor and bioimaging applications.

In this study, Lithium Niobate (LiNbO3) thin films have been successfully deposited on quartz substrates by chemical bath deposition method. The influence of different interaction time, and different deposition time were studied. The structural investigation confirmed that all LiNbO3 were hexagonal structure at (012) diffraction plane. The optical properties were conducted by UV-VIS showed an increased to 4 eV. The morphological properties showed a uniform, smooth and homogeneous structure, with a clear hexagonal structure. The grain size was reduced with increasing the interaction and deposition times. Electrical properties revealed that electrical resistivity (ρ) reached to a minimum value about (65 kΩ) for deposition time 25 min. The estimated figures of merit releaved that optimum deposition time was 15 min and stirred for 12 hrs. To demonstrate the effect of Ag nanoparticles incorporated on the LiNbO3 properties, the preparation of Ag decorated LiNbO3/Si and LiNbO3/Si heterojunction device was constructed. Different concentrations of Ag nanoparticles were synthesized and studied their structural, morphological optical and chemical properties. XRD confirmed the presence of LiNbO3 and Ag nanoparticles. FESEM showed that the Ag nanoparticles increased as Ag immersion time increased. The band gap decreased from (3.97 to 3.59 eV) as Ag immersion time increased. Photolumences spectra (PL) of Ag@ LiNbO3 films gave emission peaks at (358, 360, 363, 371 and 376) nm. Results of Raman spectrum showed that after decorated with Ag Nps the (950 cm-1 ) peaks shifted to higher intensity. The prepared device at an optimum condition of decoration has been used to prepare the heterojuction device. A clear enhancement has been achieved with the incorporation of Ag nanoparticle. The photo and dark currents with capacitance-voltage characteristics were investigated and analyzed. The ideality factor (n) was found to be enhanced and to about 2.6 for Ag@ LiNbO3/Si heterojunction device. The C-V characteristics demonstrated that the built-in potential (Vbi) was about 1.35 for Ag@ LiNbO3/Si. The photo detector showed a good stability and high; responsivity that reached to about (400, 790) nm in the UV and NIR region or pure and Ag@ LiNbO3/Si photo detector; respectively. Detectivity reached to about (400, 790) nm in the UV and NIR region for pure and Ag@ LiNbO3/Si photo detector; respectively.

This work presents a successful method for the preparation of Nb2O5 nanoparticles by employing the pulsed laser ablation in liquid (PLAL) method of a niobium metal in double deionized water. In this study, the effects of various laser parameters on the preparation of Nb2O5 nanoparticles were characterized extensively through the study of the optical, structural, morphological and chemical properties. Optimum conditions were selected after each parameter and analysis. The effect of laser fluence which ranged from 8.2 to 17.82 J/cm2 and resulted in the emergence of the orthorhombic T-Nb2O5 which was confirmed by XRD, FTIR and Raman spectroscopic analysis. The band gap dropped from 3.6 to 3.3 eV as the fluence went up. TEM and FESEM showed a spherical shaped and agglomerated particles with an average particles size range between 28 to 55 nm. Changing the number of laser pulses have led to the emergence of monoclinic H-Nb2O5 along with the orthorhombic T-Nb2O5 which was confirmed by XRD, FTIR and Raman spectroscopy. The average particles size ranged between 18 and 27 nm for TEM. While the effect of laser wavelengths, have resulted in the dominance of the monoclinic H-Nb2O5 phase over the orthorhombic T-Nb2O5. TEM and FESEM showed very small, well-defined spherical shapes with very high concentration with an average particle size 7 nm for TEM. Optical properties revealed that the band gap was about 3.4 eV. After studying the characteristics of the effect of each laser parameter on the fabrication of Nb2O5 nanoparticles, optimum conditions were selected and used for the fabrication of Au@Nb2O5 core shell nanoparticles. Different concentrations of Au nanoparticles were synthesized and their structural, morphological, chemical and optical characteristics were studied. XRD results confirmed the presence of Nb2O5 and Au confirming the formation of Au@Nb2O5 which was also confirmed by TEM results. The diameter of the core increased from 33.5 to 80.1 nm while the shell diameter changed from 5.5 to 8.05 nm with increasing the concentration of Au nanoparticles. Surface roughness found to be increase up to 68.76 nm. The absorbance spectrum revealed a red shifted as the concentration of Au nanoparticles increased, while the band gap decreased from 3.3 to 2.7 eV.

In this work, a novel approach is proposed to synthesis Raman active AgNPs and Ag@AuNPs/pre-etched Si substrate by laser assisted thermal penetration process. Four different types of superficial silver nanoparticles /pre-etched Si structures were prepared by dipping process of surface textured Si substrate in 5×10 -3 M AgNO3 (Silver nitrate) solution and different dipping times (1,4,5, and10 min). The irradiation process of Nd:YAG laser wavelength of 532 nm,600mJ energy, and 300 pulse repetition rate was employed to insert the silver nanoparticles (AgNPs) deeply inside the silicon (Si) surface. The morphological and optical properties before and after the irradiation process, show a significant value in the Specific Surface Area (S.S.A), where 72.04 m2 . g-1 was obtained for the silicon substrate of 5 min dipping time, also in this work, the deposited silver nanoparticles on a pre-etched Si substrate were modified by laser irradiation at fixed laser fluence. Different number of pulse have been employed to synthesize hybrid structure AgNPs/pre-etched Si substrate, by laser irradiation process. Four types of superficial hybrid structures were formed under fixed laser thermal of 600 mJ/cm2 with 250,300,350 and 400 pulses of laser, respectively. The results were analyezed and studied using Field Emission Scanning Electron Microscope (FE-SEM), X-Ray characteristics and optical properties as a function to number of pulses. The results showed a high dependence on the structural and optical of the hybrid structure in the laser irradiation process. The highest specific surface area of 53.008 m2 /gm at (111) plane was realized at 350 pulses. This is due to the small size (10.78 nm) of the silver nanoparticles, Finally, Ag@Au core-shell NPs/ Si (pre-etched silicon layer) were synthesised with various laser pulse repetition rates of 300,350,400,450 pulses, respectively. Also, the results were analyzed by using FE-SEM and XRD characteristics and optical properties as a function of different number of pulse. The results show extreme dependence on the structural and optical properties of Ag@Au core-shell NPs/(pre-etched silicon layer) chemical sensor on the laser irradiation process. The highest specific surface area was 41.318 m2 /gm realized at 400 pulses. The Raman and SERS spectra of the constructed hybrid chemical sensor were carried out using Rhodamine 6G concentrations ranging from (10-7 to 10-13M for core@shell NPs and 10-6 to 10- 12M for AgNPs) on pre-etched silicon .The maximum value of enhancement factor (EF) for the SERS with core@shell configured for 400 pulses was approximately 4.22×109 .While, was around 6.37×108 for the silver nanoparticles /pre-etched Si structures at 5min of dipping time.

Pulsed laser ablation, a simple, inexpensive, and useful approach, was used in this study to prepare PbS quantum dots.Two parts were used to investigate synthesis PbS QDs .First targets are submerged in distilled benzene solvent to evaluate the impact of changes in laser fluence on PbS quantum size. As a consequence of the current work, it is the first time that the synthesis of the lead sulfide nanoparticles as well as the impact of benzene on their characteristics have been described. also, the present work showed that it is possible to obtain PbS QDs by laser ablation in benzene. Three samples of PbS quantum dots are prepared by pulsed laser ablation in benzene solvent and distilled waterat at different parameter , laser fluencies of 5, 6.5, and 8 J/cm2 , with fixed number of pulses 600 hits. A PbS target was irradiated by (1064 nm) with Nd :Yag laser. Laser works in 10 ns laser pulse width and 1 Hz repetition rate. The characteristics of the as-prepared PbS QDs are confirmed by UV−vis, transmittance electron microscopy, X-ray diffraction, photoelectron spectroscopy and photoluminescence (PL). PbS X-ray diffracting pattern is produced via laser ablating inside benzene (5 J/cm2 ,600 pulses), according to XRD patterns where PbS QDs has cubical (fcc) crystal structuring with six main peaks , with 2θ values 21° ,27.7°, 30.4° ,43.6° ,51.1° and 53.6 ° correspond to the crystalline planes (021),(111),(200),(220),(311) and (222) respectively. The Photoluminescence emitting spectra is categorized via the existence of a single severe peak corresponding to the PbS at ( 5,8 J/cm2 ) at 600 pulses. According to the fluorescent peaks of the produced, the calculated band gaps had been situated at 2.5 and 2.6 eV. The quantum size was reduced to 7 to 4.5 nm in benzene and 45 – 19 in water. The UV-visible spectra for PbS QDs peaks around 321 nm , 312 and to 311 nm wave were observed for PbS nanoparticles prepared with 8 J/cm2 ,6.5 J/cm2 ,5 J/cm2 respectively. The results obtained point to the possibility for employing PbS QDs in a variety of (future research) applications, including drug administration, diagnostics, and as anticancer factors, ultimately increasing the tumor-killing effects of anticancer drugs.

In this work, (Silver, Aluminium, and Copper) bulk and nanoparticles plasmas were produced by pulsed Nd: YAG laser with 1064 nm wavelength in air (pulse duration of 9 ns and 6 Hz repetition rate) and at different pulse laser energies (400, 500, 600, 700) mJ. Optical emission spectrometer (OES) was used to diagnose the obtained plasma in air. Optical emission measurements show that the laser energy has a strong and important impact on the intensity of emission lines as the intensity of the spectral lines increases with increasing of laser energy. The effect of laser pulse energy has been studied on the plasma parameters (such as electron temperature (𝑇𝑒), electron number density (ne), Debye length (𝜆𝐷) and plasma frequency (𝑓𝑝)). The results shows, the electron temperature, the electron density and plasma frequency were increased with increasing pulse laser energy from 400 to 700 mJ for the targets used. While the Debye length is decreases with increasing laser energy. It has been observed that the value of the intensity of the spectral lines and electron temperature (𝑇𝑒), electron number density (ne), plasma frequency (𝑓𝑝) for nanomaterial greater than bulk material and the Debye length (𝜆𝐷) of nanomaterial are less than the bulk material at the same laser energy. The Energy Dispersive X-ray Spectroscopy provide a qualitative analysis and a quantitative analysis of samples. where show results the peak heights the formation of Ag at 3keV, Al at 1.5 keV and Cu at 0.9 keV. The synthetic study was carried out by means of X-ray diffraction of the elements of (Ag, Al and Cu) bulk and NPs and the results showed that all samples have a face cube crystalline for powder (Ag, Al and Cu). The reflectivity of the samples was investigated. It was noticed that the reflectivity of the materials decreases in the UV-VIS spectrum of the elements of (Ag, Al and Cu) bulk and NPs. Scanning electron microscopy (SEM) used for studying the shapes and sizes for samples. The average particle size of the samples is in the range (41- 81) nm and it was also clarified by the photographic analysis.

Porous silicon (Psi) structure has been prepared in this project via a Photo Electrochemical (PEC) anodization process. n-type silicon wafers of resistivity (10Ω.cm) in hydrofluoric acid (HF) of 24% concentration at various etching duration (15, 30, 45, 60, 75, 90 min), and current density (20mA/cm2 ). Irradiation was accomplished by diode laser beam with a power density of 15W/cm2 and a wavelength of 810 nm. X-ray diffracted (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Atomic Force Microscopy (AFM), and Gravimetric technique was employed to assess the material characteristics. FE-SEM images demonstrated that the pore width and depth of the porous layer increased with the rising of etching time, but the thickness of the walls between the pores decreased with increasing etching time. With different etching conditions, the pore shape has changed from cylindrical to spherical and rectangular. The X-ray Diffraction results revealed that the structural aspect of Psi layers stays crystalline, as also the peak of Psi structures broadened when etching time increase from 30 to75 min. The size of the nano-crystalline decreases from (16.84 to 1.96 nm). The AFM image showed changing the surface roughness values and root means a square increased from (5.666-24.94nm) and (5.960- 30.61nm), respectively with increasing etching time. The measured values of the porosity of Psi layer using the gravimetric method showed an increase (33 – 87%) with increasing etching time. When the etching time has increased from (30-75 min), the peak of the (PL) spectra exhibit a blue shift from 639.8 nm to 625 nm in the emission spectra of the as-prepared sample. In this study, electrical properties of the constructed Psi layer were investigated using a which electrical approach that represents resistance characteristics at room temperature. The obtained values of resistance increased from 25 to 73 KΩ with increasing etching time and porosity when measured at pressure atmosphere, while was reduced with the increase of vacuum ranges. Because decreases of the air molecules allow the electron charge to pass through the inside pore with increased vacuum value to 10-6 mbar. The response of the Psi enhanced with increasing vacuum and etching time.

Graphene-ZnO nanohybrid thin films were prepared by spray pyrolysis technique at 350 °C. Different Graphene sheet concentrations of (0.1, 0.2, 0.3, 0.4, and 0.5 wt. %) were used to deposit these films on quartz and silicon substrates. The monohybrid films' structural, morphological, optical, and electrical properties have been investigated. According to the XRD analysis, the structural characteristics show that the deposited films have hexagonal wurtzite for ZnO polycrystalline structure. The crystallite size, dislocation density and micro strain have indicated that the addition of graphene strongly affects the microstructure of zinc oxide films. It was found that the micro strain and dislocation density increased with graphene content rising in the ZnO matrix, while the crystallite size was decreased. The surface morphological analysis of the ZnO-Graphene films reveals that the Graphene content effectively modifies the morphologies and grain growth of the ZnO microstructure. AFM images showed how the grains are distributed and arranged on the surfaces by studying the effect of graphene concentration on the film's properties by measuring the degree of roughness (RMS) and grain size. Furthermore, FESEM images showed several morphological features on the films deposited under various graphene content. When the film surface isn’t covered with graphene, it offers high packing hexagonal grains and narrow grain size distribution. But, when the film surface is covered with a high graphene content of (0.5 wt. %), graphene nanoplates nested with zinc oxide grains were observed. In addition, the optical properties of deposited films exhibited that the maximum transmission value was found in the ZnO film. In contrast, this value will reduce with increased graphene concentration. The absorption coefficient with wavelength decreased with increased graphene concentration. The maximum energy gap was found in the pure ZnO films, which is (3.4 eV); its decreases to (2.7) eV as the concentration of Graphene increases to (0.5 wt. %). The electrical examination had the highest value at (0.5 wt. %) graphene’s concentration; this means that the nanostructure of graphene improves the electrical conductivity of ZnO. The photocurrent was increased gradually with increasing the light intensity at negative bias voltage. No photocurrent saturation with increasing light intensity was observed (good linearity characteristics). The higher current was at a graphene concentration of (0.5 wt. %) with a power intensity of 100 mW. According to the capacitive-voltage characteristics of the films, the capacitance density is reduced with growing reverse voltage due to the extension of the depletion region with increasing reverse voltage. The internal construction effort (Vbi) value range from 0.65 V to 0.3 V for ZnO/Si with (0.5 wt. %) graphene. The maximum spectral responsivity of the photodetector was noticed for G-ZnO synthesized at (0.5 wt. %) Graphene.

The future of the plasmonic devices is heavily challenged by the nanoconstruction schemes of metals which often requires rather fast, lowcost, and high-throughput fabrication techniques. Laser annealing is considered to be an unrivaled tool for surface manipulation of thin metallic films, especially with functional plasmonic devices of pre-determined morphology. The work in this thesis can be divided into two main sections: The first section studied the Nanoplasmonic sensing, based on the plasmonic resonance absorption of thin, irregularly-shaped Au nanostructures film, with a starting thickness of about 15 nm (±3 nm) sputtered on a quartz substrate, to monitor the CeO2 NPs (with an average diameter of 50 nm) film refractive index variations at different film thicknesses (90 nm, 146 nm, 172 nm, and 196 nm). Increasing the film thickness of solution-processed CeO2 NPs film, with layer-by-layer deposition on top of Au nanostructures, shows a significant redshift in the plasmonic resonance absorption of the plasmonic metal, from 580 nm to 611 nm. Such increase is related to the change in the building microstructure of the semiconductor’s film which is reflected in changing its refractive index. Plasmonic surface refractive index sensitivity of 437.5 nm/RIU with FOM of 4.2 has been recorded. The second section utilized a commercial CW CO2 laser, the wavelength of 10.6 µm and optimal power of 15W, to the surface reconstruction of thin Au films, with an initial film thickness of 15 nm (±3 nm) sputtered on quartz substrates, as plasmonic sensing platforms. The effect of two main laser parameters by AFM images on the Au film morphology has been explored namely; power density The best result was scored when 11.7 W/cm2 Average size range 110 nm FWHM 42 nm and scanning speed when 0.5 mm/sec Average size range 77 nm FWHM 44 nm has been recorded. Thermal annealing of Au nanostructured films by the electrical furnace is also been studied, at 600 oC Average size range of 116 nm FWHM 41 nm has been recorded. UV-Visible (UV-Vis) spectroscopy characterization measurements are utilized to monitor the plasmonic-induced optical absorption changes with different experimental conditions. Surface annealed Au nanofilms were then be used as a plasmonic sensing substrate to detect the size and density variation of Ag NPs, fabricated by pulsed Nd: YAG laser ablation, with a pulse duration of 7 n sec, in DI water with a wavelength of 1064 nm and different laser energies, imbedded in a solution-processed thin semiconductor material (CeO2 NPs) to form a composite film. Our plasmonic sensing structure shows a remarkable detection of variable concentrations of Ag NPs reflected by a significant red-shift in the plasmonic resonance absorption of Au nanostructures with laser ablation energy at a fixed number of pulses of 50 (50 Hz). This sensor structure is versatile and can be utilized to sense and monitor a large variety of materials and chemicals.

In this work, an efficient vacuum sensor was fabricated using a double-sided porous silicon layers (Ds-Psi). An n-type Si wafer was used to create the Ds-Psi samples using laser-assisted etching (LAE) technique. The etching process was carried out under different etching times (20, 40, 60, 80) min by 630 nm wavelength diode laser with 20 mA/cm2 current density and 100 mW/cm2 laser power density. The morphological, structural and optical characteristics of Ds-Psi layers were studied using field emission scanning electron microscopy (FE-SEM) images, Xray diffraction patterns (XRD), and the photoluminescence (PL) spectra. The obtained results, present that the surface morphology of the layer consists of mud-like structure with ultra-pores structures, The X-ray Diffraction illustrated that the Psi has a wider diffraction pattern compared with the bulk silicon and this due to the existence of silicon nano crystallites with nano regime, and the PL emission showed a specific peak centered at about (500-520) nm with decrease in the peak toward a blue shift with increasing etching time. The electrical properties of the fabricated sensors, of one side, parallel connections of Ds-Psi, and series connections of Ds-Psi sensors were investigated by analyzing the electrical resistance of porous layer at different vacuum pressures. The value of vacuum was sensed by changing the electrical resistance value of DsPsi after removing gas particles from the porous structures, thus the resistance gradually decreased after the vacuum value exceeded 10-5 mbar. The Ds-Psi sensor with series connections showed higher sensitivity than the other sensors

Photo electrochemical etching (PECE) technique was used to prepare porous silicon (PSi) samples from n-type silicon with (111) orientation. The first group of samples was prepared at different etching current density (8, 12, 16 and 20) mA/cm2 with fixed etching time and laser intensity, while the second group was prepared at different laser intensity (10, 15, 20 and 25) mA/cm2 with fixed etching time and current density. The porous silicon surface was modified by deposition of pure titanium and titanium doping with silver using pulsed laser deposition technique (PLD) to improve the gas sensing performance of these modified surfaces. Different silver concentrations of (0.5, 1.5, and 2.5) % were used. Morphological and structural features of the TiO2/PSi & TiO2:Ag/PSi nanostructures were investigated using scanning electron microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and X-ray diffraction (XRD) analysis. The XRD measurements demonstrated a strong peaks which were attributed to the porous silicon PSi, silver element has been attributed to the cubic silver nanoparticles and the detected characteristic peaks of TiO2 which led to the formation of tetragonal TiO2 (Rutile) nanoparticles. SEM images revealed that PSi surface morphology were pore-like structures. An increase in the pore diameter was observed with the increase of the current density and the intensity of the laser illumination in the PECE process. Similarly, SEM images and EDS analysis of TiO2/PSi and TiO2:Ag/PSi nanostructures confirmed the presence of TiO2 and Ag elements with different proportions, sizes, and shapes. The nanoparticles of TiO2 and TiO2:Ag structures were distributed in the form of single particles and in agglomerations around and inside the pores. The sensitivity properties of gas sensors for TiO2/PSi and TiO2:Ag/PSi nanostructures were studied. It showed improvements in sensitivity, response time, and recovery time of porous silicon as gas sensors. This is because of the high porosity, large surface area, and the small size of the TiO2:Ag structure which acted as a captures of gas molecules.The prepared sensors sensing features, such as sensitivity, response, and recovery time, have been implemented for two gases which were reducing gas (H2S with 50 ppm concentration), and an oxidizing gas (NO2 at concentration of 125 ppm). The test was performed with different operation temperatures ranging from room temperature to 200°C. Finally, the results of this study, particularly those related to gas-sensing characteristics, demonstrated that PSi enhanced by the deposition of TiO2 pure and Ag doped TiO2 provided an efficient gas-sensing developed to operate at room temperature in a relatively simple technique and inexpensive methods, and that the highest sensitivity appeared to NO2 gas at room temperature, which amounted to 93%

Cancer is the most common disease in the world and it has many traditional treatment methods. The targeted therapy method by nanocarriers is the more prefer and not harmful method for human. In this study, nanocrystalline Fe3O4 NPs were synthesized by using pulsed laser ablation in liquid. Using different Nd: YAG laser wavelengths (1064, 532 nm) and fluencies (10, 32 J/cm2 ) for each wavelength. The optical properties and the structure of the created nanoparticles were studied. These nanoparticles were characterized via employing UV-Visible absorption spectra, Fourier transforms infrared (FT-IR), Dynamic light scattering (DLS), Scanning electron microscope (SEM), atomic force microscopy and X-ray diffraction (XRD). Also in this work, Folate (FA) grafted dextran (DEX) coated superparamagnetic iron oxide nanoparticles (SPIONs) were prepared and used as a nanocarrier for Ellipticine (ET) delivery in cervical cancer in vitro. Fluorescence microscopy was utilized to evaluate the cell’s internalization ability. The suitable impact of a therapeutic dose of (SPION@DEX-ET-FA) for both cancer and healthy cell lines was estimated by using MTT assay (3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide). The flowcytometry assay and real time PCR studies were carried out to evaluate the induction of apoptosis and changes in Bax and Bcl-2 gene expression in Hela cervical cancer cells. The obtained results exhibited the producing of Fe3O4 nanoparticles having a narrow size distribution with an average size of 24±6.13 nm. The findings of the formulated SPION@DEX-ET-FA were spherical particles with average size, polydispersity, and zeta potential of 101±15.02 nm, 0.075, and, -33.8 mV, respectively. In addition, these nanoparticles (NPs) manifested a high efficiency of drug encapsulation (~73 percent). The nanoparticles demonstrated a continuous release of ET at 37°C in acidic pH. Apoptosis was calculated by Annexin-V/Propidium flow cytometry after the cancer cells treatment with SPION@DEX-ET-FA. The potential of SPION@DEX-ET-FA to upregulate Bax/Bcl-2 ratio apoptotic genes in the Hela cells was also confirmed by real-time polymerase chain reaction results. The florescence microscopy confirmed that SPION@DEX-ET-FA was able to effectively penetrate the cancer cells. The results exhibited that SPION@DEX-ETFA retained antitumor activity, and no adverse effects for healthy cells were foun

The current study aim is examining the (PbI2, CH3NH3I) that was deposited on porous silicon (n-Psi), Porous-silicon nanostructure has beenprepared in this scheme via a Photo Electrochemical (PEC) iodization method. N-type silicon-wafer of resistivity (10Ω.cm) in hydrofluoric acid (HF) of 24% attention at fixed etching time (8 min), and changing the current density (10, 14 and 18) mA/cm2 . A laser light with a strength of 20W/cm2 and a wavelength of 645 nm was used to incinerate the surface. Using two consecutive depositing processes, successful preparation of perovskite thin films was achieved. The initial stage was making thin sheets of lead iodide (PbI2) fabricated by thermal evaporation technique. PbI2 films of 200 nm thickness were deposit on a cleaned glass and Psi substrate by the thermal evaporation method at a 10-5 Torr vacuum using a high vacuum coating apparatus (Edwards type E306A). The distance linking the source and the substrate was roughly 18 cm inside the vacuum chamber, where a molybdenum boat was utilized to transport PbI2 powder. The second step was transforming PbI2 thin films. The three-dimensional perovskite was made by dissolving 4.2227 g of MAI in 20 ml of 2-propanol and then the solution was stored in a dry box under N2 pressure. Dipping the PbI2 films was done by using MAI sol (methylammonium iodide-2-propanol) and thereafter turned black, showing the composition of the CH3NH3PbI3 surface layer, with a dipping period of 10 minutes for each sample. The resulting perovskite films CH3NH3PbI3 were black in color and regular. The structural properties of the prepared thin films studied with X-ray diffraction, The PbI2.X-ray diffraction showed that the PbI2 film has a hexagonal polycrystalline structure, while the CH3NH3PbI3 thin films, show a tetragonal-phase lead iodide perovskite. FE-SEM images showed porous silicone in Photo-electrochemical etching, the pore distribution is irregular and the pore refers to the increased surface area of the silicon. SEM images of pbI2 film showed that particles became scattered and resembled gravel in size. The estimated optical energy value of thin films of PbI2 was 3.3 eV. PbI2 film has lower transmittance values at short wavelengths, but as the wavelength increased, the transmittance values gradually increased. The greatest transmittance value was 88%. From FTIR analysis, chemical bonds were determined between porous silicon and PbI2.

This study demonstrates the use of an Nd: YAG laser to generate of TiO2 NPs, and TiO2@MWCNTs nanocomposites. The first one was carried out by laser ablation of Ti target immersed in de-ionized water at different laser fluence, while the second one was achieved by irradiating of a mixture TiO2 colloidal and carbon nanotubes with different concentration ratios. Several investigations were done for specimen characterization. The FTIR results have successfully proven the formation of TiO2NPs and TiO2@MWCNTs nanocomposites. Raman spectra showed the phase crystalline of pure TiO2 NPs and TiO2@MWCNTs nanocomposites contain two main phases anatase and brookite. These results were also affirmed by XRD patterns. The FE-SEM images clearly showed that the TiO2NPs crystals with a cauliflower-like shape structure. While FE-SEM images of TiO2@MWCNTs nanocomposites showed high-quality coverage of the TiO2NPs along the MWCNTs with nest-like shape and with a minimal TiO2NPs agglomeration. TEM investigations demonstrated that the TiO2NPs have semispherical shapes with particle sizes in the range (2-75) nm. While for TiO2@MWCNTs nanocomposite, the TEM images revealed that there are two types of nanocomposites CNTs and TiO2NPs are present, the first type is the TiO2NPs that are attached to the walls of MWCNTs, and the second type is TiO2NPs were completely covered by graphene sheet and it is hardly to distinguish TiO2NPs. Optical properties showed that the TiO2 colloidal have a high absorptance at the UV region and an energy gap ranging from 3.85 to 3.4 eV depending on laser fluence. While the spectra of TiO2@MWCNTs nanocomposite showed extension to long wavelengths with bandgap energy ranging from 3.45 to 3.35 eV. The PL of TiO2 NPs showed a broad intense band in the UV-visible light range (∼350–550 nm) which decreased with increasing laser fluence. The PL results of TiO2@MWCNTs nanocomposites showed a quenching of titanium luminescence spectra. The zeta potential values were increase with the increase of the laser fluence of ablation, and the concentration ratio of MWCNTs, respectively. As a result of this research, the pulsed laser ablation in liquid is a suitable method to prepare nanomaterial structures with different shapes and sizes which makes it’s a promising candidate to apply in different applications.

The laser induced breakdown spectroscopy (LIBS) is one of the most important analytical techniques , where a suitable energy laser is used to generate plasma from targets and the spectra emitted from it are analyzed by spectroscopy . In this study, a Nd:YAG laser with a wavelength of (1064 nm), a pulse duration of (9 ns) and energies of (500 - 600 - 700 - 800) miliJoule was used to generate the spectra of plasma from the materials (zinc, copper and titanium oxide) were observed in their nano and bulk states. The spectral study was conducted and monitored in the visible region with a range (300 - 750 nm) and under atmospheric pressure. The plasma parameters have been calculated, which are the temperature of the electrons (Te) and the density of electrons (ne) . From the results, the Debye length (λd) and the plasma frequency (Fp) were calculated . The plasma temperature (Te) was calculated using the Boltzmann plot method, and the electron density (ne) using the Stark broadening method . The results were that the intensity of the spectral lines (I) , the temperature (Te), the density of electrons (ne), and the plasma frequency (Fp) increase with the increase in the laser energy. the Debye length (λd) decreases with the increase in the laser energy. It has been observed that the value of intensity of the spectral lines (I) , the temperature of electrons (Te), the density of electrons (ne) and the plasma frequency (Fp) of nanomaterials are greater than that of bulk materials, and that the Debye length (λd) of nanomaterials is less than the bulk materials and at the same laser energy. The results of synthetic tests were included in the research which are the results of X-ray diffraction (XRD) and images of the electronic scanning microscope (SEM) for nano and bulk materials.

In this study, silver oxide (Ag₂O) .thin films have been successfully prepared on glass and silicon substrates employing chemical .bath .deposition (CBD) .technique. Different .concentrations of triethanolamine (Known as TEA) (C6H15NO3) (2.5, 5, 7.5, and 10( ml, and different reaction time (0.5, 1and 1.5) hr with different reaction temperature was (25, 50,75 and 100) Cº. Structural, optical, electrical .properties were studied to determine the optimum conditions of the deposited silver oxide film in order to prepare device for P and n-type silicon. . substrates. The X.R.D analysis shows that all that Ag₂O thin films are cubic. structure with preferred .orientation at (200). FESEM .image shown a .formation of uniform. and .homogeneous crystal .grains of Ag₂O thin films and , the grain size increased with increasing of TEA .concentration. The elements.. ratios of prepared. thin films have. been diagnostic by the (EDS) measurement which revealed the formation of a .stoichiometric. film at TEA 2.5 ml. The roughness. and average. grain. Size and .RMS of the silver .oxide found to be (1.46,3.49and1.7) nm at TEA 2.5 ml, respectively. From the optical properties the values of the .direct. energy band. gap. was estimated and found to range. from (1.65-2.29) eV concentrations of TEA. The properties. of the hetrojunction. device. indicated that device had a good. . rectification. The ideality. factor (n) found to be (2.6, 3.36) for p and n-type .silicon .substrates, respectively.. The C-V characteristics demonstrate that the builtin potential (Vbi) is (0.7) for A.g₂O/n-Si and (0.2) eV for Ag₂O/p-Si. The .detectivity. was estimated for the hetrojunction detector and found (5.5*109) cm. Hz1/2 .W-1 for Ag₂O /p-Si and (3.9*109) cm. Hz1/2 .W-1. for A.g₂O/n-Si.

In this research, Zinc oxide nanoparticles have been synthesized by pulsed laser ablation (PLA) in deionized water (DIW) using different numbers of pulses. Then, it was doped with aluminum at different doping ratio using 1064 nm wavelength of NdYAG laser and constant fluence 15.48 J/cm2 . Fourier transform infrared spectroscopy (FTIR) confirmed the formation of ZnO NPs and the absorption peaks of AZO NPs. X-ray diffraction (XRD) measurement proved that the presence of the cubic structure of ZnO NPs and the formation of AZO NPs suspension. The UV-Vis absorption spectra of ZnO and AZO NPs have exhibited increasing the absorbance intensity with increasing the absorbance intensity with an increase in the number of laser pulses. While Photoluminescence (PL) analysis for ZnO and AZO NPs demonstrated two emission peaks, one of which is strong in the UV region, and the other is weak located in the visible region. Morphological properties have been examined by scanning electron microscope (SEM) and energy dispersive spectroscopy (EDs). SEM images for ZnO NPs showed that the shapes of nanoparticles change to nano-wires and small agglomerated spherical nanoparticles. And AZO SEM images showed that the shape is modified from nano-wire to spherical particles with a high particles agglomeration. EDS peaks spectrum showed that all the peaks were corresponded associated with the peaks of (Zn, O, and Al) atoms. Biomedical applications were antibacterial activity for ZnO and AZO NPs; they were carried out against two types of bacteria: (S.aureus) and (E.coli). Using two methods firstly, by liquid medium method, for pure ZnO NPs with concentration (66.6, 133.3, 200, 266.6, 333.3) 𝛍g/ml and (0.2, 0.27, 0.33, 0.42) % doping ratio for AZO, for both NPs effectiveness against S. aureus more than E. coli, and increases with increasing doping ratio. Secondly, by agar solid medium this illustrated from (IZ) diameters, which showed the same the previous results obtained from liquid medium method. Antiparasite activity and Anti-breast cancer activity were measured by MTT assay and micrographic image to calculate the growth of inhibition rate with concentration for pure ZnO NPs was (66.6, 133.3, 266.6) 𝛍g/ml and all concentration of AZO NPs. which indicated that the activity of both NPs was more effective on L. tropica than L. donovani. While anti-cancer activity reveals that AZO, NPs were more effective on breast cancer than pure ZnO NPs.

In this work Perovskite thin films, were prepared successfully using two sequential deposition process. The first step was preparing lead iodide thin films (PbI₂) with spin coating technique on a glass substrate for (15s) and (1500 r.p.m). The second step was transforming PbI₂ thin films into perovskite thin films by dipping the PbI₂ samples in MAI solution in a glove box filled with N₂ gas for 15min then dipping it immediately in 2- propanol solution to rinse for (2s) and wait for the final thin films to dry. The structural properties of the prepared thin films studied with X-ray pattern measurements; PbI₂ thin films show a polycrystalline structure with hexagonal phase. While; the CH₃NH₃PbI₃ thin films, show a tetragonal phase and found that the PbI₂ is completely transformed into CH₃NH₃PbI₃ from observing the peaks of both thin films. the morphology of the thin films were studied using FESEM images and AFM spectroscopy, FESEM images shows PbI₂ thin films look inhomogeneous and dense, with a lot of pores, while the CH₃NH₃PbI₃ look like an island with high density and non-uniformed. While AFM microscopy for PbI₂ thin films shows, the value of RMS was (14.89 nm), while for MAPbI₃ thin films the RMS value was (34.27nm) The energy bandgap was calculating by the transmittance and absorbance measurements, for PbI₂ thin films the bandgap value was 2.45eV, while the perovskite was 1.65-1.80eV also by using diffused reflectance measurements, the band gap value found to be equal to the bandgap value from the optical measurements. By using FTIR measurements, the PbI₂ thin films observed completely transformed into perovskite, with different vibrations patterns for each resulted thin films. Raman spectroscopy shows that both resulted thin films have two vibrational modes, symmetric and asymmetric vibrational modes with different peaks for both materials.These measurements have been characterized on this work are suitable for solar cell applications.

In this study, Copper doped Cobalt Oxide (Cu:Co3O4) thin films have been successfully deposited on glass and silicon substrates by chemical spray pyrolysis (CSP) technique. Different concentrations of Cu (0, 1, 3, 5, 7, 9) % were used and the substrate temperature was (350 ±5 oC). Structural, Optical, Electrical and Optoelectronic properties of thin films have been investigated by using XRD, EDS, SEM, AFM, UV-Visible spectroscopy, R-T, Hall effect, I-V, C-V and Rλ measurements. The XRD analysis reflect that all films are cubic spinal structure and a polycrystalline in nature with preferred orientation was along (111) plane. The crystallite size of the samples was maximum (34,924nm) for the unopded Co3O4 thin film, and the minimum at concentration 5% which be (30.816nm). SEM shows that the surfaces of thin films affected with Cu doping and have semi- uniform homogenous structure. The element ratio and Cu concentrations of prepared thin films have been diagnostic by EDS measurement which clarify identification with the experimental ratio. Roughness, average grain size, RMS for Copper-Cobalt Oxide were varied with Cu concentration, the minimum values was at concentration 5% of Cu. The optical properties were measured by using transmission spectra in the wavelength (300- 1100) nm. The transmittance of all thin films increase slowly with wavelength at the range (300-750) nm, and then increased rapidly at higher wavelengths. The absorption coefficient changed with Cu, and the highest one was at ratio 7%. Two optical energy gap were investigated and they decreased with increasing doping concentration. The direct band gap values ranges between (1.4-2.06) eV, and the indirect band gab ranged between (1.32-1.92) eV. The extinction coefficient decreased as the wavelength increasing. It has been found that the electrical resistivity was decreased with increasing of Cu concentration. The activation energy decreased with increasing doping concentrations and ranging from (0.128-0.366) eV. Hall Effect measurement proved that all films were p-type. p- n heterojunction properties have been studied by I-V characteristic which indicated that the films have a good rectifying. The smallest value of ideality factor (n) at 7% and built-in potential (Vbi) were at ratio 9%. The peaks of responsivity, specific detectivity and quantum efficiency increased with increasing Cu concentration.