scholarly journals ZnO QDs Deposited on Si by Sol-Gel Method: Role of Annealing Temperature on Structural and Optical Properties

2016 ◽  
Vol 10 (4) ◽  
pp. 12 ◽  
Author(s):  
A. Mohammed Al-Azawi ◽  
Hayder J. Al-Asedy ◽  
Noriah Bidin ◽  
Khaldoon N. Abbs.
Keyword(s):  
Optical Properties ◽  
Annealing Temperature ◽  
Ostwald Ripening ◽  
Sol Gel ◽  
Structural And Optical Properties ◽  
Wurtzite Phase ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Zno Qds

Zinc acetate, propanol, and ethanolamine are used to synthesize ZnO quantum dots (QDs) via the sol–gel method. Spin coating at 220°C is then employed to prepare ZnO thin films consist of QDs. The effects of thermal annealing temperature on the structural and optical properties of the samples are investigated. The prepared QDs are characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and photoluminescence spectroscopy (PL). XRD patterns reveal the crystalline nature of samples existing in the hexagonal wurtzite phase. Increasing annealing temperatures bring about changes to the crystal orientation through the c-axis and increase the size of the QDs from ~10 nm to ~22 nm; this increment can be explained by a coarsening mechanism and the Ostwald ripening process. The observed broadening of X-ray peaks confirms the evolution of crystalline phases in the ZnO QDs. Quantitative analysis of size-dependent strain effects is performed through the Williamson-Hall model. The QD mean size estimated from FESEM and XRD displays high consistency. Room-temperature PL peaks of 3.37ev are attributed to the radiative recombination of electrons and holes from the ZnO QDs/Si interface.

Effect of annealing temperature on the structural and optical properties of ZnO thin films prepared by sol–gel method

Ionics ◽  
2010 ◽  
Vol 16 (9) ◽  
pp. 815-820 ◽  
Author(s):  
Yidong Zhang ◽  
Wenjun Fa ◽  
Fengling Yang ◽  
Zhi Zheng ◽  
Pingyu Zhang
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Zno Thin Films ◽  
Structural And Optical Properties ◽  
Gel Method ◽  
Sol Gel Method

Influence of Annealing Temperature on Structural and Optical Properties of Undoped and Al-Doped Nano-ZnO Films Prepared by Sol–Gel Method

2016 ◽  
Vol 8 (4) ◽  
pp. 878-883 ◽  
Author(s):  
Vladimir Gevorgyan ◽  
Anna Reymers ◽  
Mikayel Arzakantsyan ◽  
Kilbock Lee ◽  
Jinho Ahn ◽  
...  
Keyword(s):  
Optical Properties ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Zno Films ◽  
Structural And Optical Properties ◽  
Nano Zno ◽  
Gel Method ◽  
Sol Gel Method

Effects of annealing temperature on the structural and optical properties of ZnO thin films prepared by sol–gel method

2016 ◽  
Vol 09 (06) ◽  
pp. 1750010 ◽  
Author(s):  
Jitao Li ◽  
Dinyu Yang ◽  
Xinghua Zhu ◽  
Hui Sun ◽  
Xiuying Gao ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Annealing Temperature ◽  
Energy Gap ◽  
Sol Gel ◽  
Heat Treating ◽  
Zno Thin Films ◽  
Structural And Optical Properties ◽  
Gel Method ◽  
Sol Gel Method

ZnO thin films have been prepared by sol–gel method in this paper. Zinc acetate, ethanol and mono-ethanolamine (MEA) were used as a metal precursor, solvent and stabilizer, respectively. The structural and optical properties of ZnO thin films were investigated and found to be strongly dependent on the annealing temperature. X-ray diffraction patterns revealed that as the annealing temperature increased, the crystalline quality of the samples became better. The atomic force microscope images of the samples show larger and compact grains at higher heat-treating temperature. The ultraviolet–visible transmittance spectra indicated that as the temperature increased, the transmittance improved and the energy gap became larger (from 3.11[Formula: see text]eV at 400[Formula: see text]C to 3.22[Formula: see text]eV at 500[Formula: see text]C). The photoluminescence spectra presented a variety of emission peaks, two strong peaks at 390[Formula: see text]nm and 469[Formula: see text]nm, respectively, from the intrinsic emission and point defects, and the intensity of these peaks decreased with the increase of temperature.

Influence of Cd doping on structural and optical properties of (Cd, Al)-codoped ZnO powders synthesized via sol–gel method

2015 ◽  
Vol 645 ◽  
pp. 529-534 ◽  
Author(s):  
Libing Duan ◽  
Xiaoru Zhao ◽  
Yajun Wang ◽  
Hao Shen ◽  
Wangchang Geng ◽  
...  
Keyword(s):  
Optical Properties ◽  
Sol Gel ◽  
Structural And Optical Properties ◽  
Gel Method ◽  
Sol Gel Method ◽  
Cd Doping ◽  
Zno Powders

Annealing Effects on the Physical and Magnetic Properties of Tb1.5Y1.5Fe5O12 Films Nanoparticles Prepared by Sol-Gel Method

2013 ◽  
Vol 756 ◽  
pp. 91-98 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Annealing Temperature ◽  
Quartz Substrate ◽  
Sol Gel ◽  
Lattice Parameter ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Iron Garnet

Terbium –substituted yttrium iron garnet (Tb1.5Y1.5Fe5O12) films nanoparticles were successfully prepared by a sol-gel method. The films were deposited on the quartz substrate using spin coating technique. To study effect of annealing temperature, the annealing process was executed at 700, 800 and 900 °C in air for 2 hours. The X-ray diffraction (XRD) proved that the pure phase of garnet structure was detected for the film annealed at 900 °C. The lattice parameter increased with the increment of annealing temperature and the highest value of 12.35 Å was obtained at 900 °C. Field Emission Scanning Electron Microscope (FE-SEM) results showed that the particle size increased from 43nm to 56nm as annealing temperature increased from 700 to 900°C. The film’s thickness also affected by increasing of annealing temperature and become thin at 900 °C due to densification process occurred at high annealing temperature. The elemental compositions of the Tb1.5Y1.5Fe5O12 film were detected using an Energy Dispersive X-raySpectroscopy (EDX). Magnetic properties at room temperature were measured using a Vibrating Sample Magnetometer (VSM).The saturation magnetization Ms increased with the annealingtemperature and showed a high value of 104emu/cm3, but the coercivity Hc of the film was decreased due to the increment of the particle size. Normal 0 21 false false false MS X-NONE X-NONE MicrosoftInternetExplorer4 Terbium –substituted yttrium iron garnet (Tb1.5Y1.5Fe5O12) films nanoparticles were successfully prepared by a sol-gel method. The films were deposited on the quartz substrate using spin coating technique. To study effect of annealing temperature, the annealing process was executed at 700, 800 and 900°C in air for 2 hours. The X-ray diffraction (XRD) proved that the pure phase of garnet structure was detected for the film annealed at 900 °C. The lattice parameter increased with the increment of annealing temperature and the highest value of 12.35 Å was obtained at 900 °C. Field Emission Scanning Electron Microscope (FE-SEM) results showed that the particle size increased from 43nm to 56nm as annealing temperature increased from 700 to 900 °C. The film’s thickness also affected by increasing of annealing temperature and become thin at 900 °C due to densification process occurred at high annealing temperature. The elemental compositions of the Tb1.5Y1.5Fe5O12 film were detected using an Energy Dispersive X-ray Spectroscopy (EDX). Magnetic properties at room temperature were measured using a Vibrating Sample Magnetometer (VSM).The saturation magnetization Ms increased with the annealing temperature and showed a high value of 104emu/cm3, but the coercivity Hc of the film was decreased due to the increment of the particle size. st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

The Structural, Magnetic and Optical Properties of Ni-Mg-Zn Ferrite Prepared With Different Complexing Agents via Sol-Gel Method

2021 ◽  
Author(s):  
Yanchun Zhang ◽  
Aimin Sun ◽  
Zhaxi Suonan
Keyword(s):  
Optical Properties ◽  
Electron Microscope ◽  
Sol Gel ◽  
Complexing Agents ◽  
Complexing Agent ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Zn Ferrite ◽  
Vis Spectroscopy

Abstract Different complexing agents were used to prepare Ni-Mg-Zn ferrite with the composition formula Ni0.2Mg0.2Zn0.6Fe2O4 via sol-gel method, which included citric acid, oxalic acid, egg white and EDTA. The Ni0.2Mg0.2Zn0.6Fe2O4 ferrite with no complexing agent was also prepared as a comparison. The chemical phases of samples were analyzed by the X-ray diffraction (XRD), which indicated that samples had spinel phase structure. The lattice constants of samples are in the range of 8.3980 ~ 8.4089 Å. The composition and structure were further studied by fourier transform infrared spectroscopy (FTIR). There were two typical characteristic bands related to the stretching vibrations of spinel ferrite in FTIR spectra. Scanning electron microscope (SEM) micrographs and transmission electron microscope (TEM) images showed that the particles have the shape of spherical cube. Energy dispersive spectrometer (EDS) analyzed the elements and ingredients of samples, which included Ni, Mg, Zn, Fe and O. X-ray photoelectron spectroscopy (XPS) is used to examine further the elemental composition and chemical state of sample prepared with EDTA as complexing agent. The optical properties of samples were investigated by photoluminescence spectra and UV-Vis spectroscopy. Vibrating sample magnetometer (VSM) was used to characterize magnetic properties, hysteresis loops revealed the ferrimagnetism behavior of prepared samples.

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