The electronic structure of molecular beam epitaxy grown InAs (110)

1992 ◽  
Vol 70 (10-11) ◽  
pp. 1099-1103 ◽  
Author(s):  
D. M. Swanston ◽  
A. B. McLean ◽  
D. N. McIlroy ◽  
D. Heskett ◽  
R. Ludeke ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Photoelectron Spectroscopy ◽  
Molecular Beam ◽  
Reciprocal Lattice ◽  
Lone Pair ◽  
Surface States ◽  
Surface Zone ◽  
High Symmetry ◽  
Initial State ◽  
Valence Bands

The initial state dispersion of the two-dimensional electronic surface states on the nonpolar InAs(110) surface has been measured using momentum-resolved photoelectron spectroscopy with synchrotron radiation. The InAs(110) surfaces were grown using molecular beam epitaxy on a GaAs(110) substrate. The A5 surface state, which arises from the surface As lone pair, is split off from the bulk bands away from the surface zone centre and is clearly visible in the photoemission spectra at the high symmetry points ([Formula: see text], [Formula: see text] and [Formula: see text]) of the surface reciprocal lattice. Lower lying surface states overlap more strongly with the bulk bands and consequently it is harder to determine their band dispersion. To alleviate this problem we have applied nonlinear line shape analysis techniques to the valence bands. We demonstrate the viability of this approach to extract the binding energy and width of optical transitions.

scholarly journals Photoelectron Spectroscopy of Solids ? VUV Band Structure Studies

1990 ◽  
Vol 43 (5) ◽  
pp. 651 ◽  
Author(s):  
Robert Leckey ◽  
John Riley
Keyword(s):  
Band Structure ◽  
Photoelectron Spectroscopy ◽  
Electronic Band Structure ◽  
Surface States ◽  
Initial State ◽  
Emission Data ◽  
Electronic Band ◽  
Radiation Sources ◽  
Valence Bands ◽  
Variable Energy

The electronic band structure of solids, including states specific to the surface, may now be explored in very great detail by photoelectron spectroscopy. Variable energy photon sources (synchroton radiation sources) coupled with advanced angle resolving electron spectrometers permit access to emission from specific points within the complete Brillouin zone. The technique of band mapping has now reached a stage where the small k-dependent changes to individual valence bands due to the effects of introduced lattice strain can be observed, for example. The relative importance of emission from surface states, as opposed to bulk band states, can be demonstated dramatically using off-normal emission data. Angle resolved constant initial state spectroscopy has recently been shown to provide details of excited state bandstructure and has clarified the involvement of surface and bulk Umklapp scattering in the photoemission process. The above capabilities of photoelectron spectroscopy are discussed, using metallic and semiconducting examples, and are related to interface problems in general.

scholarly journals Experimental Evidence of Topological Surface States in Mg3Bi2 Films Grown by Molecular Beam Epitaxy

2019 ◽  
Vol 36 (11) ◽  
pp. 117303 ◽  
Author(s):  
Tong Zhou ◽  
Xie-Gang Zhu ◽  
Mingyu Tong ◽  
Yun Zhang ◽  
Xue-Bing Luo ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Experimental Evidence ◽  
Molecular Beam ◽  
Surface States ◽  
Topological Surface

scholarly journals Hexagonal Boron Nitride Tunnel Barriers Grown on Graphite by High Temperature Molecular Beam Epitaxy

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Yong-Jin Cho ◽  
Alex Summerfield ◽  
Andrew Davies ◽  
Tin S. Cheng ◽  
Emily F. Smith ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
High Temperature ◽  
Molecular Beam Epitaxy ◽  
Boron Nitride ◽  
Photoelectron Spectroscopy ◽  
Molecular Beam ◽  
Hexagonal Boron Nitride ◽  
Graphite Substrate ◽  
Force Microscopy ◽  
Atomic Force

Abstract We demonstrate direct epitaxial growth of high-quality hexagonal boron nitride (hBN) layers on graphite using high-temperature plasma-assisted molecular beam epitaxy. Atomic force microscopy reveals mono- and few-layer island growth, while conducting atomic force microscopy shows that the grown hBN has a resistance which increases exponentially with the number of layers, and has electrical properties comparable to exfoliated hBN. X-ray photoelectron spectroscopy, Raman microscopy and spectroscopic ellipsometry measurements on hBN confirm the formation of sp2-bonded hBN and a band gap of 5.9 ± 0.1 eV with no chemical intermixing with graphite. We also observe hexagonal moiré patterns with a period of 15 nm, consistent with the alignment of the hBN lattice and the graphite substrate.

Growth and Characterization of AlBN Polycrystalline Thin Film by Radio-Frequency Plasma-Assisted Molecular Beam Epitaxy

2006 ◽  
Vol 301 ◽  
pp. 95-98 ◽  
Author(s):  
Masashi Yamashita ◽  
Yukari Ishikawa ◽  
Hitoshi Ohsato ◽  
Noriyoshi Shibata
Keyword(s):  
Thin Film ◽  
Molecular Beam Epitaxy ◽  
Radio Frequency ◽  
Photoelectron Spectroscopy ◽  
Molecular Beam ◽  
High Energy ◽  
Radio Frequency Plasma ◽  
Group Iii ◽  
Frequency Plasma

An AlBN thin film with a boron content (B/(Al+B)) of 0.1 or 0.3 was obtained by radio-frequency plasma-assisted molecular beam epitaxy (RF-MBE) using EB-guns as group-III element sources and an RF radical source for nitrogen supply. We compared the characteristics of the film with those of AlN and BN films. By reflective high-energy electron diffraction (RHEED), we observed ring patterns in the AlBN film. The X-ray photoelectron spectroscopy (XPS) N1s peak of the AlBN film was observed at a binding energy between the peaks of AlN and BN. There was no evidence for phase separation in the film.

Epitaxial Dy2O3 Thin Films Grown on Ge(100) Substrates by Molecular Beam Epitaxy

2010 ◽  
Vol 1252 ◽  
Author(s):  
Md. Nurul Kabir Bhuiyan ◽  
Mariela Menghini ◽  
Christel Dieker ◽  
Jin Won Seo ◽  
Jean-Pierre Locquet ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Photoelectron Spectroscopy ◽  
Molecular Beam ◽  
High Mobility ◽  
High Energy ◽  
Epitaxial Relationship ◽  
Dysprosium Oxide ◽  
X Ray ◽  
Force Microscopy ◽  
Diffraction Patterns

AbstractDysprosium oxide (Dy2O3) films are grown epitaxially on high mobility Ge(100) substrates by molecular beam epitaxy system. Reflection high energy electron diffraction patterns and X-ray diffraction spectra show that single crystalline cubic Dy2O3 films are formed on Ge(100) substrates. The epitaxial-relationship is identified as Dy2O3 (110)║Ge(100) and Dy2O3 [001]║Ge[011]. Atomic force microscopy results show that the surface of the Dy2O3 film is uniform, flat and smooth with root mean square surface roughness of about 4.6Å. X-ray photoelectron spectroscopy including depth profiles confirms the composition of the films being close to Dy2O3. TEM measurements reveal a sharp, crystalline interface between the oxide and Ge.

scholarly journals Фотоэмиссионные исследования электронной структуры GaN, выращенного методом молекулярно-пучковой эпитаксии с плазменной активацией азота

2019 ◽  
Vol 61 (12) ◽  
pp. 2294
Author(s):  
С.Н. Тимошнев ◽  
А.М. Мизеров ◽  
Г.В. Бенеманская ◽  
С.А. Кукушкин ◽  
А.Д. Буравлев
Keyword(s):  
Electronic Structure ◽  
Charge Transfer ◽  
Synchrotron Radiation ◽  
Photoelectron Spectroscopy ◽  
Molecular Beam ◽  
Experimental Studies ◽  
Surface States ◽  
Li Adsorption ◽  
Semiconductor Character

The results of experimental studies of the electronic and photoemission properties of an epitaxial GaN layer grown on a SiC/Si(111) substrate by plasma assisted molecular beam epitaxy are presented. The electronic structure of the GaN surface and ultrathin Li/GaN interface was first studied in situ under ultrahigh vacuum conditions under different Li coverages. The experiments were performed using photoelectron spectroscopy with synchrotron radiation in the photon energy range of 75–850 eV. The photoemission spectra in the region of the valence band and surface states and the photoemission spectra from the N 1s, Ga 3d, Li 2s core levels were studied for different submonolayer Li coverages. It is established that Li adsorption causes significant changes in the general form of the spectra induced by charge transfer between the Li layer and the lower N and Ga layers. It is established that the GaN surface has predominantly N-polarity. The semiconductor character of the Li / GaN interface is shown.

Structural and Optical Properties of Zn1-XCoXO Thin Films Fabricated by Laser Molecular Beam Epitaxy

2011 ◽  
Vol 295-297 ◽  
pp. 1958-1963
Author(s):  
Jing Zhi Yang ◽  
Li Juan Fu ◽  
Xiao Peng Qi ◽  
Hong Yun Li
Keyword(s):  
Thin Films ◽  
Molecular Beam Epitaxy ◽  
Photoelectron Spectroscopy ◽  
Molecular Beam ◽  
Ambient Pressure ◽  
Visible Region ◽  
Hexagonal Structure ◽  
Axis Orientation ◽  
X Ray ◽  
Laser Molecular Beam Epitaxy

Zn1-xCoxO thin films on sapphire (0001) substrates were synthesized by laser molecular beam epitaxy (LMBE) method at various temperatures under a work ambient pressure of 5.0 x 10-5Pa condition. X-ray diffraction (XRD) spectra, UV–visible transmission spectra and X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) spectra were employed to characterize the properties of samples. All samples were of wurtzite hexagonal structure with the preferential c-axis-orientation. Co2+ions incorporated into ZnO lattice and substituted for Zn2+ions. ZnLMM Auger spectrum implied Zn interstitials existed in sample. The optical transmission of all samples was relatively high in visible region. Two PL emission peaks located at 418 nm and 490 nm were assigned to the electron transition from the Zn interstitials to the top of the valence band and from the Zn interstitials to the Zn vacancies, respectively.

Changes in Optical Properties of GaAsN During Annealing

2005 ◽  
Vol 891 ◽  
Author(s):  
Ting Liu ◽  
Sandeep Chandril ◽  
Eric D. Schires ◽  
Nianqiang Wu ◽  
Xinqi Chen ◽  
...  
Keyword(s):  
Optical Properties ◽  
Molecular Beam Epitaxy ◽  
Quantum Dot ◽  
Photoelectron Spectroscopy ◽  
Molecular Beam ◽  
Annealing Temperature ◽  
Emission Spectra ◽  
X Ray ◽  
Annealing Temperatures ◽  
Gaas Substrates

ABSTRACTGaAs1−xNx layers and quantum dot-like structures were grown on (100) GaAs substrates by molecular beam epitaxy. The dependence of photoluminescence emission spectra on annealing temperature is consistent with literature at lower temperatures but after annealing at 750 °C a net red-shift is consistently observed. X-ray photoelectron spectroscopy measurements indicate that for different annealing times and temperatures, the nitrogen and arsenic surface concentrations changed compared to that of as-grown samples, specifically arsenic is lost from the material. Raman measurements are consistent with the trends in photoluminescence and also suggest the loss of arsenic occurs at higher annealing temperatures in both samples capped with GaAs and uncapped samples.

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