Emad Hasabeldaim

University of the Free State | ufs · Department of Physics

Highly preferential c-axis (002) orientated ZnO:Zn films were successfully prepared in different growth atmospheres using the pulsed laser deposition technique. The stress parameters in the films were determined as −2.81 GPa, −1.03 GPa and −0.08 GPa for the thin films deposited in O2, Ar and vacuum, respectively. X-ray photoelectron spectroscopy (X...

The pulsed laser deposition (PLD) substrate temperature and post-annealing temperature are effective methods to control the film optical and structural properties. The structure, morphology and optical properties of the deposited and post-annealed PLD ZnO:Zn films were studied. The films were deposited at different substrate temperatures of 50 °C,...

ZnO thin films were successfully synthesized by the sol-gel method using the spin coater technique. The films were annealed at 600 °C in air for two hours and in Ar/H2(5%) flow for 30 and 60 minutes, respectively. Structural analysis, surface morphology and characterization, as well as optical analysis (photoluminescence and cathodeluminescence (CL...

Commercial ZnO:Zn and undoped ZnO with a hexagonal wurtzite structure (JCPDS 80-0075) were studied. The direct optical bandgaps were 3.25 and 3.28 eV for the undoped and ZnO:Zn, respectively. Undoped ZnO exhibited strong ultraviolet band to band emission as well as weak deep level defect emission around the green, orange, and red regions. ZnO:Zn em...

Eu3+ ion doped CaF2 thin film was successfully prepared using the hydrothermal method and coated by a spin coating technique. A thin layer of ZnO was deposited on the Eu3+ doped CaF2 thin film by pulsed laser technique. Incorporation of the dopant into the CaF2 crystal was confirmed by x-ray powder diffraction and x-ray photoelectron spectroscopy (...

Luminescence properties of CaF2:Tb3+ nanoparticles were studied in order to investigate the effect of CaF2 native defects on the photoluminescence dynamics of Tb3+ ions. Incorporation of Tb ions into the CaF2 host was confirmed by X-ray diffraction and X-ray photoelectron spectroscopy. Cross-relaxation energy transfer was observed from the photolum...

Au nanoparticles (NPs) interleaved between ZnO films were prepared on Si substrates and CaF2:Tb³⁺ thin films were then spin coated on top. The Au NPs were ∼43 nm in diameter and exhibited a plasmonic absorption band at ∼544 nm, which red-shifted with increasing ZnO layer thickness. Photoluminescence (PL) of the Si/ZnO/Au/ZnO/CaF2:Tb³⁺ structure exh...

The surface composition and stability of ZnGa2O4:Mn²⁺ green phosphor were evaluated using Auger electron spectroscopy (AES) under electron beam irradiation in vacuum and oxygen (4.0 × 10⁻⁷ mbar). The surface chemistry was monitored while measuring the cathodoluminescence (CL) intensity. The Auger peak-to-peak heights (APPHs) of Zn and Ga were stabl...

Eu (3 mol%) doped ZnO thin films were deposited by pulsed laser deposition at different oxygen partial pressures. The structure, morphology and luminescence properties of the films were studied. The scanning electron microscopy images revealed that the films deposited in vacuum have smoother surfaces compared to the oxygen pressure films. When exci...

A highly c-axis orientated Eu³⁺ doped ZnO (ZnO:Eu³⁺) thin film was successfully deposited by pulsed laser deposition in an oxygen working atmosphere. The structure, morphology, chemical analysis and luminescence properties of the sample were investigated. The effect of electron beam irradiation on the surface state, chemical and luminescence proper...

ZnO thin films doped with Eu³⁺ up to 4 mol% were successfully prepared using a sol-gel spin coating technique. The structure, morphology, chemical analysis and luminescence of the films were studied. X-ray photoelectron spectroscopy (XPS) analysis for the Eu 3d core shells confirmed the presence of divalent (Eu²⁺) and trivalent (Eu³⁺) states. Time...

Eu ³⁺ doped ZnO thin films were successfully prepared using the spin coating technique. X-ray diffraction confirmed that the undoped films had high crystallinity and preferred orientation along the c-axis, although the crystallinity and the preferred orientation deteriorated with increasing Eu ³⁺ doping concentration. The average particle sizes est...

Bright green luminescence at 500 nm was obtained from chemical bath deposited ZnO nanorods after annealing in a reducing atmosphere (H 2 /Ar) at 700 °C for 30 min. Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and secondary electron microscopy (SEM) were used to study the effect of electron beam irradiation on the cathod...

Preferentially c-axis oriented ZnO nanorods were grown on a ZnO seed layer spin coated on a crystalline silicon substrate. A low-temperature aqueous chemical growth method using the chemical bath deposition technique was used to grow the ZnO nanorods. The samples were annealed at 700 °C in a reducing atmosphere (H2/Ar) with a relative ratio of 5%:9...

ZnO thin films were successfully synthesized by the sol-gel method using the spin coater technique. The films were annealed at 600 °C in air for two hours and in a H2 flow for different time periods. The un-annealed film showed an amorphous structure. The c-axis orientation along (002) plane was obtained for the films annealed in air and in the H2...

The dependence of the structural and optical properties of ZnO:Zn thin films deposited by Pulsed Laser Deposition at different preparation conditions have been investigated. All the films showed highly preferential c-axis orientation, and their crystallinities were improved with increasing the substrate temperature. The stress in the thin films has...