Scanning Tunneling Spectroscopy Investigation of the Strained Si1−xGex-on-Si Band Offsets

2000 ◽  
Vol 618 ◽  
Author(s):  
Xiangdong Chen ◽  
Xiang-Dong Wang ◽  
Kou-Chen Liu ◽  
Dong-Won Kim ◽  
Sanjay Banerjee
Keyword(s):  
Valence Band ◽  
Conduction Band ◽  
Scanning Tunneling Spectroscopy ◽  
Tunneling Spectroscopy ◽  
Conduction Band Edge ◽  
Scanning Tunneling ◽  
Band Offset ◽  
Valence Band Offset ◽  
Strained Si ◽  
Band Offsets

ABSTRACTThe band offsets and band gap are the most important parameters that determine the electrical and optical behavior of a heterojunction. In situscanning tunneling spectroscopy (STS) was employed to measure the valence band offset of strained Si1−xGex-on-Si (100) for the first time. The valence band offsets of strained Si0.77Ge0.23and Si0.59Ge0.41on Si(100) are found to be 0.21eV and 0.36eV, respectively. The results are in good agreement with theory and with results from other experimental methods. Due to band bending and surface states, it is difficult to determine the conduction band edge at the interface of Si1−xGex/Si exactly, but the conduction band offset is found to be much smaller than the valence band offset

Scanning Tunneling Spectroscopy Investigation of the Strained Si1−xGex Band Structure

2000 ◽  
Vol 15 (6) ◽  
pp. 1257-1260 ◽  
Author(s):  
Xiangdong Chen ◽  
Xiang-Dong Wang ◽  
Kou-Chen Liu ◽  
Dong-Won Kim ◽  
Sanjay Banerjee
Keyword(s):  
Valence Band ◽  
Conduction Band ◽  
Scanning Tunneling Spectroscopy ◽  
Tunneling Spectroscopy ◽  
Conduction Band Edge ◽  
Scanning Tunneling ◽  
Band Offset ◽  
Valence Band Offset ◽  
Strained Si ◽  
Band Offsets

The band offsets and band gap are the most important parameters that determine the electrical and optical behavior of a heterojunction. In situ scanning tunneling spectroscopy was employed to measure the valence-band offset of strained Si1−xGex-on-Si (100) for the first time. The valence-band offsets of the strained Si0.77Ge0.23 and Si0.59Ge0.41 on Si(100) were found to be 0.21 and 0.36 eV, respectively. The results were in good agreement with theory and with results from other experimental methods. Due to band bending and surface states, it was difficult to determine the conduction band edge at the interface of the Si1−xGex/Si exactly but we found that the conduction band offset is much smaller than the valence-band offset.

Determination of Band Offsets in Heterostructured Colloidal Nanorods Using Scanning Tunneling Spectroscopy

Nano Letters ◽  
2008 ◽  
Vol 8 (9) ◽  
pp. 2954-2958 ◽  
Author(s):  
Dov Steiner ◽  
Dirk Dorfs ◽  
Uri Banin ◽  
Fabio Della Sala ◽  
Liberato Manna ◽  
...  
Keyword(s):  
Scanning Tunneling Spectroscopy ◽  
Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Band Offsets

Electron and Hole Confinement in GaInN/GaN and AlGaN/GaN Quantum Wells

2001 ◽  
Vol 693 ◽  
Author(s):  
A. Hangleiter ◽  
S. Lahmann ◽  
C. Netzel ◽  
U. Rossow ◽  
P. R. C. Kent ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Valence Band ◽  
Conduction Band ◽  
Band Offset ◽  
Valence Band Edge ◽  
Valence Band Offset ◽  
Time Resolved ◽  
Conduction Band Offset ◽  
Hole Confinement ◽  
Weak Electron

AbstractWe show that the strong bowing of the bandgap of GaInN, which is primarily due to bowing of the valence band edge, translates into a strongly composition dependent ratio of the conduction band offset to the valence band offset with respect to GaN. For common In mole fractions of 0-20 % this leads to a reversal of the band offset ratio and to very weak electron con nement. This theoretical picture is veri ed by comparing results of time-resolved spectroscopy on asymmetric AlGaN/GaInN/GaN and AlGaN/GaN/AlGaN quantum wells. Since electron con nement is much stronger for GaN/AlGaN wells than for GaInN/GaN wells, the effect of asymmetry is very weak for the former and fairly strong for the latter.

Compositionally Dependent Band Offsets In Aln/AlxGa1-xN Heterojunctions Measured By Using X-Ray Photoelectron Spectroscopy

1997 ◽  
Vol 482 ◽  
Author(s):  
R.A. Beach ◽  
E.C. Piquette ◽  
R.W. Grant ◽  
T.C. McGill
Keyword(s):  
Valence Band ◽  
Photoelectron Spectroscopy ◽  
Valence Band Maximum ◽  
Core Level ◽  
Band Offset ◽  
Valence Band Offset ◽  
Band Offsets ◽  
Band Maximum ◽  
X Ray ◽  
Al Content

AbstractAlthough GaN has been extensively studied for applications in both light emitting and high power devices, the AlN/GaN valence band offset remains an area of contention. Values quoted in the literature range from 0.8eV (Martin)[1] to 1.36eV (Waldrop)[2]. This paper details an investigation of the AIN/AlxGa1-xN band offset as a function of alloy composition. We find an AlN/AlxGa1-xN valence band offset that is nearly linear with Al content and an end point offset for AlN/GaN of 1.36 ± 0.1 eV. Samples were grown using radio frequency plasma assisted molecular beam epitaxy and characterized with x-ray photoelectron spectroscopy(XPS). Core-level and valence-band XPS data for AIN (0001) and AlxGa1-xN (0001) samples were analyzed to determine core-level to valence band maximum (VBM) energy differences. In addition, oxygen contamination effects were tracked in an effort to improve accuracy. Energy separations of core levels were obtained from AlN/AlxGa1-xN(0001) heterojunctions. From this and the core-level to valence band maximum separations of the bulk materials, valence band offsets were calculated.

scholarly journals Band offsets of InGaP∕GaAs heterojunctions by scanning tunneling spectroscopy

2008 ◽  
Vol 103 (7) ◽  
pp. 073704 ◽  
Author(s):  
Y. Dong ◽  
R. M. Feenstra ◽  
M. P. Semtsiv ◽  
W. T. Masselink
Keyword(s):  
Scanning Tunneling Spectroscopy ◽  
Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Band Offsets

Direct Optical Measurement of the valence band offset of p+ Si1−x−yGexCy/p− Si (100) by Heterojunction Internal Photoemission

1998 ◽  
Vol 533 ◽  
Author(s):  
C. L. Chang ◽  
L. P. Rokhinson ◽  
J. C. Sturm
Keyword(s):  
Valence Band ◽  
Optical Measurement ◽  
Chemical Vapor ◽  
Band Alignment ◽  
Band Offset ◽  
Valence Band Offset ◽  
Strained Si ◽  
Internal Photoemission ◽  
Capacitance Voltage ◽  
Absorption Measurements

AbstractOptical absorption measurements have been performed to study the effect of carbon on the valence band offset of compressively strained p+ Si1−x−yGexCy/(100) p− Si heterojunction internal photoemission structures grown by Rapid Thermal Chemical Vapor Deposition (RTCVD) with substitutional carbon levels up to 2.5%. Results indicated that carbon decreased the valence band offset by 26 ± 1 meV/ %C. Results from optical measurement in this study agreed with previous data from capacitance-voltage measurements. Based on previous reports of carbon effect on the bandgap of compressively strained Si1−x−yGexCy, our work suggests that the effect of carbon incorporation on the band alignment of Si1−x−yGexCy/Si is to reduce the valence band offset, with a negligible effect on the conduction band alignment.

scholarly journals The Synthesis of NiO/TiO2Heterostructures and Their Valence Band Offset Determination

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Z. H. Ibupoto ◽  
M. A. Abbasi ◽  
X. Liu ◽  
M. S. AlSalhi ◽  
M. Willander
Keyword(s):  
Valence Band ◽  
Conduction Band ◽  
Photoelectron Spectroscopy ◽  
Glass Substrate ◽  
Band Offset ◽  
Valence Band Offset ◽  
X Ray ◽  
Conduction Band Offset ◽  
P Type ◽  
Fto Glass

In this work, a heterojunction based on p-type NiO/n-type TiO2nanostructures has been prepared on the fluorine doped tin oxide (FTO) glass substrate by hydrothermal method. Scanning electron microscopy (SEM) and X-Ray diffraction techniques were used for the morphological and crystalline arrays characterization. The X-ray photoelectron spectroscopy was employed to determine the valence-band offset (VBO) of the NiO/TiO2heterojunction prepared on FTO glass substrate. The core levels of Ni 2p and Ti 2p were utilized to align the valence-band offset of p-type NiO/n-type TiO2heterojunction. The valence band offset was found to be∼0.41 eV and the conduction band was calculated about∼0.91 eV. The ratio of conduction band offset and the valence-band offset was found to be 2.21.

scholarly journals Atomic-scale determination of band offsets at the Gd2O3/GaAs (100) hetero-interface using scanning tunneling spectroscopy

2011 ◽  
Vol 99 (21) ◽  
pp. 212101 ◽  
Author(s):  
Y. P. Chiu ◽  
B. C. Huang ◽  
M. C. Shih ◽  
J. Y. Shen ◽  
P. Chang ◽  
...  
Keyword(s):  
Scanning Tunneling Spectroscopy ◽  
Tunneling Spectroscopy ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Band Offsets
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