MBE Growth and Properties of Wide Band-Gap II-VI Strained-Layer Superlattice

1992 ◽  
Vol 242 ◽  
Author(s):  
Hailong Wang ◽  
Jie Cui ◽  
Aidong Shen ◽  
Liang Xu ◽  
Yunliang Chen ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Wide Band ◽  
Far Infrared ◽  
Atomic Layer ◽  
X Ray Diffraction ◽  
Wide Band Gap ◽  
Strained Layer ◽  
Pl Spectra ◽  
Reflectivity Spectra ◽  
Strained Layer Superlattice

ABSTRACTThe (ZnSe) /(ZnS ), strained layer super-lattices (SLSs) on (100) GaAs and (ZnTe)/(ZnSe) SLSs on (100) InP have been grown by molecular beam epitaxy (MBE) and atomic layer epitaxy (ALE). The structural characteristics of these SLSs were investigated in situ RHEED observation, low-angle X-ray diffraction spectra, TED image and AES analysis. The optical properties of the SLSs, such as refractive index of superlattice materials, photoluminescence (PL) spectra, transient PL spectra, Raman spectra, far-infrared reflectivity spectra and Optical nonlinear have been studied.

Growth and Characterization of Znsete Epilayers and Superlattices

1990 ◽  
Vol 198 ◽  
Author(s):  
M. C. Phillips ◽  
Y. Rajakarunanayake ◽  
J. O. Mccaldin ◽  
R. H. Miles ◽  
D. H. Chow ◽  
...  
Keyword(s):  
Equilibrium Phase ◽  
Wide Band ◽  
Alloy System ◽  
Miscibility Gap ◽  
X Ray Diffraction ◽  
Wide Band Gap ◽  
Light Emitting ◽  
X Ray ◽  
Light Emitting Devices ◽  
Pl Spectra

ABSTRACTLittle has been published about Te-rich ZnSexTel−x grown at low temperatures, in spite of some successes in the fabrication of wide band gap light emitting devices from ZnSeTe alloys grown at higher temperatures. We present x-ray diffraction and photoluminescence (PL) spectra for ZnSeTe epilayers and ZnSeTe/ZnTe superlattices grown by molecular beam epitaxy (MBE). These we compare with measurements on ZnTe, ZnSe and CdZnTe epilayers and on CdZnTe/ZnTe superlattices grown under similar conditions and also with data published for ZnSeTe alloys grown at high temperatures. Equilibrium phase diagrams for the ZnSeTe alloy system suggest a large miscibility gap at MBE growth temperatures; this may account for some unusual features in the (PL) spectra and for large line widths in the x-ray data. In spite of these possible miscibility problems, we find that ZnSeTe alloys luminesce brightly.

Evaluation on Crystal and Optical Properties of AlN:Er Prepared by RF magnetron sputtering method

2006 ◽  
Vol 955 ◽  
Author(s):  
Shin-ichiro Uekusa ◽  
Takahiko Ohno ◽  
Tomoyuki Arai ◽  
Hiroshi Miura
Keyword(s):  
Thin Films ◽  
Wide Band ◽  
Rf Magnetron Sputtering ◽  
Reactive Magnetron ◽  
X Ray Diffraction ◽  
Wide Band Gap ◽  
Nitrogen Gas ◽  
Pl Spectra ◽  
Strong Luminescence ◽  
Transmission Window

ABSTRACTThe Er that is rare earth element causes luminescence at 1540 nm, which is a low loss transmission window in silica-based fibers used in optical communications. Moreover, it is known that the temperature quenching of the luminescence of Er becomes smaller with the wide band gap of the host material. We report on the photoluminescence (PL) characteristic and X-ray diffraction (XRD) of AlN:Er thin films which are deposited by RF reactive magnetron co-sputtering method. All the thin films were deposited by RF reactive magnetron co-sputtering method from a 99.999 % Al target and 99.99 % Er chips in a nitrogen gas (99.9998 %) atmosphere. The thin films were achieved with a discharge power of 250 W in a total pressure of 5.0∼10-3 Torr, and the deposition times were one hour. After the deposited, these samples were annealed for 30 minutes in the temperature range from 400 to 900° in a nitrogen gas (99.999 %) atmosphere with an infrared lamp heater. PL spectra of AlN:Er were measured using the 325 nm line of a He-Cd laser at 15 K. Consequently, we observed PL spectra around 1500 nm. The strong luminescence of peak wavelength at 1538 nm is based on the intra-4f emitting centers of Er. We report systematically the experimental results of PL and XRD.

Optical and structural characteristics of InGaAs/GaAs strained-layer superlattice

1998 ◽  
Author(s):  
Mei Li ◽  
Xueqian Li ◽  
Xiaowei Song ◽  
Zhongjiu Ge ◽  
Xingde Zhang
Keyword(s):  
Structural Characteristics ◽  
Strained Layer ◽  
Strained Layer Superlattice

Epitaxial Growth of Aluminum Nitride on Sapphire and Silicon

1994 ◽  
Vol 358 ◽  
Author(s):  
K. Dovidenko ◽  
S. Oktyabrsky ◽  
J. Narayan ◽  
M. Razeghi
Keyword(s):  
Epitaxial Growth ◽  
Substrate Surface ◽  
Wide Band ◽  
X Ray Diffraction ◽  
Wide Band Gap ◽  
High Quality ◽  
Microstructural Characteristics ◽  
X Ray ◽  
Si Substrates ◽  
Transmission Electron

ABSTRACTThe microstructural characteristics of wide band gap semiconductor, hexagonal A1N thin films on Si(100), (111), and sapphire (0001) and (10ī2) were studied by transmission electron microscopy (TEM) and x-ray diffraction. The films were grown by MOCVD from TMA1 + NH3 + N2 gas mixtures. Different degrees of film crystallinity were observed for films grown on α-A12O3 and Si substrates in different orientations. The epitaxial growth of high quality single crystalline A1N film on (0001) α-Al2O3 was demonstrated with a dislocation density of about 2*10 10cm−2 . The films on Si(111) and Si(100) substrates were textured with the c-axis of A1N being perpendicular to the substrate surface.

Stress origin and relaxation in epitaxial AlN thin films on SiC

2001 ◽  
Vol 696 ◽  
Author(s):  
Ravi Bathe ◽  
R.D. Vispute ◽  
Daniel Habersat ◽  
R. P. Sharma ◽  
T. Venkatesan ◽  
...  
Keyword(s):  
Thin Films ◽  
Rutherford Backscattering Spectrometry ◽  
Wide Band ◽  
X Ray Diffraction ◽  
Wide Band Gap ◽  
X Ray ◽  
Force Microscopy ◽  
Ion Channeling ◽  
Atomic Force ◽  
Highly Strained

AbstractWe have investigated the epitaxy, surfaces, interfaces, and defects in AlN thin films grown on SiC by pulsed laser deposition. The stress origin, evolution, and relaxation in these films is reported. The crystalline structure and surface morphology of the epitaxially grown AlN thin films on SiC (0001) substrates have been studied using x-ray diffraction (θ–2θ, ω, and Ψ scans) and atomic force microscopy, respectively. The defect analysis has been carried out by using Rutherford backscattering spectrometry and ion channeling technique. The films were grown at various substrate temperatures ranging from room temperature to 1100 °C. X-ray diffraction measurements show highly oriented AlN films when grown at temperatures of 750- 800 °C, and single crystals above 800 °C. The films grown in the temperature range of 950 °C to 1000 °C have been found to be highly strained, whereas the films grown above 1000 °C were found to be cracked along the crystallographic axes. The results of stress as a function of growth temperature, thermal mismatch, growth mode, and buffer layer thickness will be presented, and the implications of these results for wide band gap power electronics will be discussed.

Studies on the Preparation and Properties of Sheet Ni-Doped ZnO

2011 ◽  
Vol 356-360 ◽  
pp. 435-438
Author(s):  
Ling Cao ◽  
Dai Zong An ◽  
Yan Xin Wang ◽  
Shan Shan He ◽  
Chuang Ju Dong
Keyword(s):  
Growth Parameters ◽  
Wide Band ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Wide Band Gap ◽  
Manipulation System ◽  
Doped Zno ◽  
Zno Crystal ◽  
Analysis System

ZnO is a direct wide band-gap Ⅱ-Ⅵ semiconductor material. For decades, ZnO has gained more and more attention as a wide band semiconductor. This paper introduced a modified homogeneous precipitation method to prepare sheet Ni-doped ZnO crystal. The preparation process was studied and the mechanism of this method was discussed. The properties of the sheet Ni-doped ZnO crystal and the effects of growth parameters on the quality of sheet Ni-doped ZnO crystal were studied using XTJ30-micro image manipulation system, thermal analysis system, X-ray diffraction. etc.

Electron Diffusion in ZnO Nanomaterial: An Ac Impedance Investigation

2011 ◽  
Vol 312-315 ◽  
pp. 393-398
Author(s):  
Roshidah Rusdi ◽  
Norlida Kamarulzaman ◽  
Mohamed Nor Sabirin ◽  
Zurina Osman ◽  
Azilah Abd Rahman
Keyword(s):  
Sol Gel ◽  
Wide Band ◽  
Ac Impedance ◽  
X Ray Diffraction ◽  
Wide Band Gap ◽  
Electron Diffusion ◽  
Electron Conduction ◽  
Diffusion Characteristics ◽  
Zno Nanomaterials ◽  
Electrical Components

ZnO is a wide band gap semiconductor with many applications such as in solar cells, varistors, and other electrical components. The ZnO material was synthesized using a sol-gel method. The material was characterized using X-Ray diffraction (XRD) and scanning electron microscopy (SEM). The material is pure and single phase. Electron conduction in ZnO nanomaterials was done using alternating current (ac) impedance. The frequency ranges of the measurements used were 1x 10-3 Hz to 1x 106 Hz and the ac impedance measurements were done within a temperature range of 60oC to 100oC. Nyquist plots were drawn and bulk resistances were obtained. Subsequently, conductivity values were calculated and the diffusion characteristics were obtained. From further analysis of the conductivities with temperature, the diffusion of electrons in the material was studied. It was found that the conductivity increased with the increase of temperature which meant that the rate of diffusion of the electrons through the materials also increased. An Arrhenius relation was concluded for the electron diffusion in the ZnO nanomaterials.

Nanostructure Assembly of Indium Sulphide Quantum Dots and Their Characterization

2008 ◽  
Vol 8 (2) ◽  
pp. 689-694 ◽  
Author(s):  
B. Vigneashwari ◽  
V. Ravichandran ◽  
P. Parameswaran ◽  
S. Dash ◽  
A. K. Tyagi
Keyword(s):  
Quantum Dots ◽  
Colloidal Suspension ◽  
Wide Band ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Wide Band Gap ◽  
X Ray ◽  
Glass Substrates ◽  
Series Of Experiments ◽  
Indium Sulphide

Nanocrystals (∼5 nm) of the semiconducting wide band gap material β-In2S3 obtained by chemical synthesis through a hydrothermal route were characterized for phase and compositional purity. These nanoparticles exhibited quantum confinement characteristics as revealed by a blue-shifted optical absorption. These quantum dots of β-In2S3 were electrically driven from a monodisperse colloidal suspension on to conducting glass substrates by Electophoretic Deposition (EPD) technique and nanostructural thin films were obtained. The crystalline and morphological structures of these deposits were investigated by X-ray diffraction and nanoscopic techniques. We report here that certain interesting nanostructural morphologies were observed in the two-dimensional quantum dot assemblies of β-In2S3. The effect of the controlling parameters on the cluster growth and deposit integrity was also systematically studied through a series of experiments and the results are reported here.

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