Fermi energy band dispersion and orbital symmetry of Bi2Sr2CaCu2Oy studied by non-polarized-light two-dimensional photoelectron spectroscopy

2007 ◽  
Vol 467 (1-2) ◽  
pp. 43-50 ◽  
Author(s):  
Chikako Sakai ◽  
Fumihiko Matsui ◽  
Nobuaki Takahashi ◽  
Sakura Nishino Takeda ◽  
Hiroshi Daimon
Keyword(s):  
Fermi Energy ◽  
Photoelectron Spectroscopy ◽  
Energy Band ◽  
Polarized Light ◽  
Two Dimensional ◽  
Orbital Symmetry ◽  
Band Dispersion

Oriented Growth of Model Molecules of Polyethylene and Poly(tetrafluoroethylene) (n-C44H90 and n-C24F50) and Angle-resolved UPS Study of Their Intramolecular Energy Band Dispersion (E=E(k)) Relation

2002 ◽  
Vol 734 ◽  
Author(s):  
Daisuke Yoshimura ◽  
Takayuki Miyamae ◽  
Sinji Hasegawa ◽  
Yukinobu Hosoi ◽  
Yoko Sakurai ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Energy Band ◽  
Film Structure ◽  
Level Shift ◽  
Oriented Growth ◽  
Good Correspondence ◽  
Chain Molecules ◽  
Infrared Reflection ◽  
Band Dispersion

ABSTRACTWe report on the recent progress of our continued effort for the preparation and characterization of well oriented films of tetratetracontane (n-C44H90) and perfluorotetracosane (n-C24F50), which are good model molecules of fundamental polymers, polyethylene (CH2)n and poly(tetrafluoroethylen) (CF2)n, vacuum-deposited on metal surfaces. When the surface of the metal substrate was oxidized, the deposited chain molecules are aligned with their molecular axes vertically standing on the surface, while they lie flat on the surface when atomically clean Cu(100) surface was used. In the case of n-C44H90 on Cu (100), low-energy electron diffraction (LEED) studies revealed that the molecules were also azimuthally aligned with the chain axis almost parallel with the <100> and <010> axis, and infrared reflection-absorption spectroscopy (IR-RAS) enabled detailed studies of the film structure at increasing film thickness._By applying the technique of angle-resolved ultraviolet photoelectron spectroscopy (ARUPS) to these flat-lying molecules, the intramolecular energy-band dispersion relation could be determined, The results agreed well with the results deduced from the previous work using vertically standing molecules assuming an inner potential V0. of –5 eV, confirming the validity of the estimation of V0. Excellent agreement was found between the observed and simulated spectra using the independent-atomic-center (IAC) approximation. Also the value of the vacuum level shift by molecular deposition was deduced for TTC/Cu(100) system to be – 0.3 eV. As for n-C24F50, the E(k) relation deduced in our previous study using vertically standing molecules showed discrepancy with band calculations. The detailed reexamination of the experimental data using IAC calculations for the previous report gave more realistic estimation of V0, and the newly deduced E(k) relation using this data showed good correspondence with theoretical band calculations, thus removing the difficulty in the previous work.

scholarly journals Stereophotographs of Atomic Structures by Circularly-polarized Light Two-dimensional Photoelectron Spectroscopy

Hyomen Kagaku ◽  
2005 ◽  
Vol 26 (12) ◽  
pp. 746-751 ◽  
Author(s):  
Fumihiko MATSUI ◽  
Yukako KATO ◽  
Fang Zhun GUO ◽  
Tomohiro MATSUSHITA ◽  
Hiroshi DAIMON
Keyword(s):  
Photoelectron Spectroscopy ◽  
Polarized Light ◽  
Two Dimensional ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Atomic Structures

Two dimensional Sr silicate grown on Si(001) studied using X-ray Photoelectron Spectroscopy

2006 ◽  
Vol 132 ◽  
pp. 87-90
Author(s):  
M. El Kazzi ◽  
G. Delhaye ◽  
S. Gaillard ◽  
E. Bergignat ◽  
G. Hollinger
Keyword(s):  
Photoelectron Spectroscopy ◽  
Two Dimensional ◽  
X Ray

scholarly journals Polarization-sensitive photodetectors based on three-dimensional molybdenum disulfide (MoS2) field-effect transistors

Nanophotonics ◽  
2020 ◽  
Vol 9 (16) ◽  
pp. 4719-4728
Author(s):  
Tao Deng ◽  
Shasha Li ◽  
Yuning Li ◽  
Yang Zhang ◽  
Jingye Sun ◽  
...  
Keyword(s):  
Molybdenum Disulfide ◽  
Field Effect ◽  
High Performance ◽  
Field Effect Transistors ◽  
Three Dimensional ◽  
Polarized Light ◽  
Optical Field ◽  
Two Dimensional ◽  
Polarization Ratio ◽  
Two Dimensional Materials

AbstractThe molybdenum disulfide (MoS2)-based photodetectors are facing two challenges: the insensitivity to polarized light and the low photoresponsivity. Herein, three-dimensional (3D) field-effect transistors (FETs) based on monolayer MoS2 were fabricated by applying a self–rolled-up technique. The unique microtubular structure makes 3D MoS2 FETs become polarization sensitive. Moreover, the microtubular structure not only offers a natural resonant microcavity to enhance the optical field inside but also increases the light-MoS2 interaction area, resulting in a higher photoresponsivity. Photoresponsivities as high as 23.8 and 2.9 A/W at 395 and 660 nm, respectively, and a comparable polarization ratio of 1.64 were obtained. The fabrication technique of the 3D MoS2 FET could be transferred to other two-dimensional materials, which is very promising for high-performance polarization-sensitive optical and optoelectronic applications.

scholarly journals Photoelectron spectroscopy of the protoporphyrin IX dianion

2021 ◽  
Author(s):  
Jemma Gibbard ◽  
Connor Jack Clarke ◽  
Jan RR Verlet
Keyword(s):  
Photoelectron Spectroscopy ◽  
Femtosecond Lasers ◽  
Protoporphyrin Ix ◽  
Photoelectron Spectra ◽  
Two Dimensional

Two-dimensional photoelectron spectroscopy using nanosecond and femtosecond lasers has been used to study the Protopophyrin IX dianion at photon energies between 1.8 - 4.1 eV. The photoelectron spectra indicated the...

scholarly journals Extremely flat band in bilayer graphene

2018 ◽  
Vol 4 (11) ◽  
pp. eaau0059 ◽  
Author(s):  
D. Marchenko ◽  
D. V. Evtushinsky ◽  
E. Golias ◽  
A. Varykhalov ◽  
Th. Seyller ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Bilayer Graphene ◽  
Flat Band ◽  
Honeycomb Lattice ◽  
Band Model ◽  
Two Dimensional ◽  
Band Formation ◽  
Constant Energy ◽  
Mexican Hat ◽  
Band Dispersion

We propose a novel mechanism of flat band formation based on the relative biasing of only one sublattice against other sublattices in a honeycomb lattice bilayer. The mechanism allows modification of the band dispersion from parabolic to “Mexican hat”–like through the formation of a flattened band. The mechanism is well applicable for bilayer graphene—both doped and undoped. By angle-resolved photoemission from bilayer graphene on SiC, we demonstrate the possibility of realizing this extremely flattened band (< 2-meV dispersion), which extends two-dimensionally in a k-space area around the K¯ point and results in a disk-like constant energy cut. We argue that our two-dimensional flat band model and the experimental results have the potential to contribute to achieving superconductivity of graphene- or graphite-based systems at elevated temperatures.

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