Direct evaluation of hole effective mass of SnS–SnSe solid solutions with ARPES measurement

Valence band dispersions of single-crystalline SnS1-xSex solid solutions were observed by angle-resolved photoemission spectroscopy (ARPES). The hole effective masses, crucial factors in determining thermoelectric properties, were directly evaluated. They decrease...

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Model of DOS near the Top of Valence Band in Strained Si1-xGex/(001)Si

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.55-57.979 ◽

2011 ◽

Vol 55-57 ◽

pp. 979-982

Author(s):

Jian Jun Song ◽

Heng Sheng Shan ◽

He Ming Zhang ◽

Hui Yong Hu ◽

Guan Yu Wang ◽

...

Keyword(s):

Effective Mass ◽

Valence Band ◽

Theoretical Basis ◽

Hole Mobility ◽

Physical Parameters ◽

Density Of State ◽

Strained Si ◽

Hole Effective Mass ◽

Effective Masses ◽

Material Physics

Strained Si1-xGextechnology has been widely adopted to enhance hole mobility. One of the most important physical parameters is density of state near the top of valence band in strained Si1-xGexmaterials. In this paper, we first obtained the hole effective mass along arbitrarily k wavevector directions, the hole isotropic effective masses and density of state effective mass of hole in strained Si1-xGex/(001)Si with the framework of K.P theory. And then, model of density of state near the top of valence band in strained Si1-xGex/(001)Si materials was established, which can provide valuable references to the understanding on its material physics and theoretical basis on the other important physical parameters.

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Light Effective Mass in the Widely-Dispersed Valence Band of Single Crystalline Rubrene Observed by High-Resolution Angle-Resolved Ultraviolet Photoelectron Spectroscopy

MRS Proceedings ◽

10.1557/proc-1197-d07-31 ◽

2009 ◽

Vol 1197 ◽

Author(s):

Yasuo Nakayama ◽

Shin-ichi Machida ◽

Steffen Duhm ◽

Qian Xin ◽

Akihiro Funakoshi ◽

...

Keyword(s):

High Resolution ◽

Charge Carrier ◽

Single Crystals ◽

Effective Mass ◽

Valence Band ◽

Photoelectron Spectroscopy ◽

Ultraviolet Photoelectron Spectroscopy ◽

Hole Effective Mass ◽

Single Crystalline ◽

Laser Illumination

AbstractHigh-resolution angle resolved ultraviolet photoelectron spectroscopy measurements were conducted on rubrene single crystals successfully through relief of the sample charging assisted by a laser illumination. Significant dispersion of the valence band was clearly resolved. The band width W and the hole effective mass mh* were estimated to be 0.4 eV and 0.7m0, respectively, along the most conductive direction. The present results strongly suggest that the transport nature in rubrene single crystals should be described in the band transport framework of a delocalized charge carrier.

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Valence band structure of the ZnO(1 0 1¯ 0) surface studied by angle-resolved photoemission spectroscopy

Applied Surface Science ◽

10.1016/j.apsusc.2004.06.100 ◽

2004 ◽

Vol 237 (1-4) ◽

pp. 343-347 ◽

Cited By ~ 6

Author(s):

K. Sawada ◽

Y. Shirotori ◽

K. Ozawa ◽

K. Edamoto ◽

M. Nakatake

Keyword(s):

Band Structure ◽

Valence Band ◽

Photoemission Spectroscopy ◽

Valence Band Structure ◽

Angle Resolved Photoemission Spectroscopy

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Effect of band structure adjustment based of Cu site on the thermoelectric properties of BiCuSeO

10.21203/rs.3.rs-195109/v1 ◽

2021 ◽

Author(s):

Bo Feng

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Seebeck Coefficient ◽

Effective Mass ◽

Valence Band ◽

Thermoelectric Properties ◽

Density Of States ◽

First Principles Calculation ◽

Temperature Range ◽

Ti Doping

Abstract The effect of Ti doped at Cu site on the thermoelectric properties of BiCuSeO was studied by experimental method and first principles calculation. The results show that Ti doping can cause the lattice contraction and decrease the lattice constant. Ti doping can increase the band gap and lengthen the Cu/Ti-Se bond, resulting in the decrease of carrier concentration. Ti doping can reduce the effective mass and the Bi-Se bond length, correspondingly improve the carrier mobility. Ti doping can decrease the density of states of Cu-3d and Se-4p orbitals at the top of valence band, but Ti-4p orbitals can obviously increase the density of states at the top of valence band and finally increase the electrical conductivity in the whole temperature range. With the decrease of effective mass, Ti doping would reduce the Seebeck coefficient, but the gain effect caused by the increase of electrical conductivity is more than the benefit reduction effect caused by the decrease of Seebeck coefficient, and the power factor shows an upward trend. Ti doping can reduce Young's modulus, lead to the increase of defect scattering and strain field, correspondingly reduce the lattice thermal conductivity and total thermal conductivity. It is greatly increased for the ZT values in the middle and high temperature range, with the highest value of 1.04 at 873 K.

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