TY  - BOOK
AU  - Samah Mohamed Hamdy Ahmed 
AU  - Lotfia Elnadi , 
AU  - Mostafa Elsayed , 
AU  - Yahia Badr , 
TI  - Spectroscopic study of Eu-doped nano semiconductors prepared by laser ablation or RF sputtering / 
PY  - 2013///
CY  - Cairo : 
PB  - Samah Mohamed Hamdy Ahmed , 
KW  - Rare-earth ions
KW  - Semiconductors
KW  - Zinc oxide
N1  - Thesis (Ph.D.) - Cairo University - National Institute of Laser Enhanced Sciences - Department of Laser Science and  Interaction; Issued also as CD
N2  - Rare-earth-doped wide-bandgap semiconductors are an interesting class of inorganic luminescent materials with complex optical properties and widespread potential applications in optoelectronics. Undoped and Eu-doped GaN powders have been synthesized by the co-precipitation method followed by nitridation at high temperature. The X-ray diffraction (XRD) patterns reveal the single-phase wurtzite structure of the synthesized undoped and Eu-doped GaN powders. The morphology of the samples was examined by the field emission scanning electron microscope (FE-SEM) and the high resolution transmission electron microscope (HR-TEM), and it was shown that the micron-sized particles are composed of agglomerated nano-crystallites. This agglomeration may be due to the absence of any surfactant during the preparation. Under above bandgap excitation, the room-temperature photoluminescence (PL) of both samples show the characteristic GaN band-edge emission peak at 363 nm, as well as a broad defect-related emission band centered at around 415 nm. The Eu-doped GaN sample, under below bandgap excitation at 464 nm, exhibited red emission peaks at 593 nm and 616 nm, corresponding to the ⁵D₀ {u2192} ⁷F₁ and  ⁵D₀ {u2192} ⁷F₂ transitions, respectively, within the 4f-shell of Eu³⁺ ions ions
UR  - http://172.23.153.220/th.pdf
ER  -