GaAs surface states observed by x‐ray photoemission

1979 ◽  
Vol 16 (5) ◽  
pp. 1300-1301 ◽  
Author(s):  
R. Ludeke ◽  
L. Ley
Keyword(s):  
Surface States ◽  
Gaas Surface ◽  
X Ray

X‐ray analysis of GaAs surface reconstructions in H2and N2atmospheres

1990 ◽  
Vol 56 (20) ◽  
pp. 2025-2027 ◽  
Author(s):  
D. W. Kisker ◽  
P. H. Fuoss ◽  
K. L. Tokuda ◽  
G. Renaud ◽  
S. Brennan ◽  
...  
Keyword(s):  
Gaas Surface ◽  
X Ray ◽  
Surface Reconstructions

Characterization of GaAs Surface State by Hard X-ray Photoemission Spectroscopy

2014 ◽  
Author(s):  
Y. Saito ◽  
J. Iihara ◽  
T. Yonemura ◽  
K. Yamaguchi ◽  
D. Tsurumi
Keyword(s):  
Surface State ◽  
Gaas Surface ◽  
Photoemission Spectroscopy ◽  
X Ray

Deep level transient spectroscopy study of GaAs surface states treated with inorganic sulfides

1988 ◽  
Vol 53 (12) ◽  
pp. 1059-1061 ◽  
Author(s):  
D. Liu ◽  
T. Zhang ◽  
R. A. LaRue ◽  
J. S. Harris ◽  
T. W. Sigmon
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Surface States ◽  
Gaas Surface ◽  
Spectroscopy Study ◽  
Transient Spectroscopy

Improvement of Atomic-Layer-Deposited Al2O3/GaAs Interface Quality through a Novel Sulfuration Method

2011 ◽  
Vol 287-290 ◽  
pp. 2327-2331
Author(s):  
Ge Ming Tan ◽  
Qing Qing Sun ◽  
Hong Liang Lu ◽  
Peng Fei Wang ◽  
Shi Jin Ding ◽  
...  
Keyword(s):  
Atomic Layer ◽  
Oxide Thickness ◽  
Gaas Surface ◽  
Interface Quality ◽  
Mos Capacitors ◽  
X Ray ◽  
Native Oxides ◽  
Capacitance Voltage ◽  
Chemical Passivation ◽  
Elemental Arsenic

The absence of stable oxide/GaAs interface greatly holds back the step of GaAs-based MOSFETs fabrication. In this letter, we report on the chemical passivation of n-type GaAs surface by introducing a new sulfuration method. X-ray photon-electron spectroscopy (XPS) analyses indicate that most GaAs native oxides and elemental arsenic (As) can be more effectively removed by treating the GaAs surface in CH3CSNH2solution compared to the traditional (NH4)2S solution. Capacitance-Voltage characteristics of the CH3CSNH2treated MOS capacitors also presents reduced interfacial layer and equivalent oxide thickness which are well consisted with the conclusion obtained by XPS.

Dirac States of 2D Topological Insulators: Effect of Heterovalent Dopant-Content

2019 ◽  
Vol 25 (6) ◽  
pp. 1437-1441 ◽  
Author(s):  
Salma Khatun ◽  
Amlan J. Pal
Keyword(s):  
Fermi Energy ◽  
Dirac Point ◽  
Surface States ◽  
Scanning Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Metallic State ◽  
X Ray Diffraction ◽  
Dopant Content ◽  
X Ray ◽  
Transmission Electron

AbstractWe have studied Bi2Se3 at its 2D-limit using scanning tunneling spectroscopy (STS). Bulk Bi2Se3 is a well-known topological insulator having gapless surface states. In the 2D limit, the interior of the material exhibits a band gap, whereas the periphery shows a gapless metallic state having a Dirac point. We demonstrate a method to tune the Fermi energy and hence the Dirac point of Bi2Se3 nanoplates through doping at the anionic site. For this purpose, STS measurements were carried out on the Bi2Se3 system. We have used bromide as a dopant, which turns the material to n-type in nature. As a result, STS studies infer that the Fermi energy (EF) shifted toward the conduction band and consequently the Dirac point could be found to move away from Fermi energy. Through STS measurements, we have demonstrated a correlation between the shift of Dirac point position and the dopant content. The size, shape, and compositions of Bi2Se3 nanoflakes and concentration of bromine in the doped nanostructures were determined using transmission electron microscopy, associated energy dispersive X-ray spectroscopy analysis, and X-ray diffraction.

Highly Luminescent Inverted ZnS/CdS Core/Shell Quantum Dots

2008 ◽  
Vol 8 (8) ◽  
pp. 3949-3954 ◽  
Author(s):  
Madhulika Sharma ◽  
D. Gupta ◽  
D. Kaushik ◽  
A. B. Sharma ◽  
R. K. Pandey
Keyword(s):  
Quantum Dots ◽  
Grazing Angle ◽  
Surface States ◽  
Shell Structures ◽  
Luminescence Spectroscopy ◽  
Core Shell ◽  
Additional Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Synthesis of highly luminescent and monochromatic inverted core–shell structures utilizing ZnS/CdS quantum dots (QDs) has been investigated. The core/shell quantum dots have been characterized using grazing angle X-ray diffraction (XRD), Transmission electron microscopy, Optical absorption and luminescence spectroscopy. The results suggested that passivation of surface states along with an increased localization of electron and hole in CdS shell layer, give rise to increased monochromaticity with higher quantum yield. The possibility of using the inverted core–shell structure as an additional parameter for tuning the color of luminescence has also been discussed.

scholarly journals Optical and Thermoelectric Properties of Surface-Oxidation Sensitive Layered Zirconium Dichalcogenides ZrS2−xSex (x = 0, 1, 2) Crystals Grown by Chemical Vapor Transport

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 327
Author(s):  
Thalita Maysha Herninda ◽  
Ching-Hwa Ho
Keyword(s):  
Single Crystals ◽  
Thermoelectric Properties ◽  
Surface States ◽  
Chemical Vapor ◽  
Surface Oxidation ◽  
Vapor Transport ◽  
Chemical Vapor Transport ◽  
X Ray ◽  
Transmission Electron ◽  
Work Structure

In this work, structure, optical, and thermoelectric properties of layered ZrS2−xSex single crystals with selenium composition of x = 0, 1, and 2 were examined. Single crystals of zirconium dichalcogenides layer compounds were grown by chemical vapor transport method using I2 as the transport agent. X-ray diffraction (XRD) and high-resolution transmission electron microscope (HRTEM) results indicated that ZrS2−xSex (x = 0, 1, and 2) were crystalized in hexagonal CdI2 structure with one-layer trigonal (1T) stacking type. X-ray photoelectron and energy dispersive X-ray measurements revealed oxidation sensitive behavior of the chalcogenides series. Transmittance and optical absorption showed an indirect optical gap of about 1.78 eV, 1.32 eV, and 1.12 eV for the ZrS2−xSex with x = 0, 1, and 2, respectively. From the result of thermoelectric experiment, ZrSe2 owns the highest figure-of merit (ZT) of ~0.085 among the surface-oxidized ZrS2−xSex series layer crystals at 300 K. The ZT values of the ZrS2−xSex (x = 0, 1, and 2) series also reveal increase with the increase of Se content owing to the increase of carrier concentration and mobility in the highly Se-incorporated zirconium dichalcogenides with surface states.

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