scholarly journals Resonant leaky-mode spectral-band engineering and device applications

2004 ◽  
Vol 12 (23) ◽  
pp. 5661 ◽  
Author(s):  
Y. Ding ◽  
R. Magnusson
Keyword(s):  
Spectral Band ◽  
Leaky Mode ◽  
Band Engineering ◽  
Device Applications

scholarly journals Band Engineering of Carbon Nanotubes for Device Applications

Matter ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 664-695
Author(s):  
Liu Qian ◽  
Ying Xie ◽  
Shuchen Zhang ◽  
Jin Zhang
Keyword(s):  
Carbon Nanotubes ◽  
Band Engineering ◽  
Device Applications

Modulation Doped Si/SiGe Heterostructures

1991 ◽  
Vol 220 ◽  
Author(s):  
F. Schäffler ◽  
Daimler-Benz AG
Keyword(s):  
Room Temperature ◽  
Field Effect Transistor ◽  
High Electron ◽  
Dopant Distribution ◽  
Band Engineering ◽  
Main Emphasis ◽  
Device Applications ◽  
Effect Transistor ◽  
P Type ◽  
Thermal Stability Of

ABSTRACTAn overview of SiGe-based, modulation doped heterostructures is given. Strained layer handling, a prerequisite for realizing both n- and p-type devices, Is treated in terms of band engineering. The main emphasis is put on recent results obtained with high-electron mobility n-type Si/SiGe structures. Hall, Shubnikov-deHaas, and cyclotron resonance measurements are presented. The thermal stability of the heterostructures and the dopant distribution are treated with respect to device applications. Room temperature and 77K dc-measurements on very recent modulation doped field effect transistor (MODFET) implementations using implanted source/drain contacts are discussed. Device concepts with n- and p-type MODFETs combined in a superior complementary layout (CMODFET) are proposed.

scholarly journals Giant charge-to-spin conversion in ferromagnet via spin-orbit coupling

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yuki Hibino ◽  
Tomohiro Taniguchi ◽  
Kay Yakushiji ◽  
Akio Fukushima ◽  
Hitoshi Kubota ◽  
...  
Keyword(s):  
Time Reversal ◽  
Spin Current ◽  
Electrical Current ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Spin Conversion ◽  
Band Engineering ◽  
Perpendicular Magnetization ◽  
Large Enhancement ◽  
Device Applications

AbstractConverting charge current into spin current via the spin Hall effect enables efficient manipulation of magnetization by electrical current. However, its geometrical restriction is a serious obstacle to device applications because it prevents switching of perpendicular magnetization in the absence of an external field. To resolve this issue, ferromagnetic materials have attracted attentions because their time reversal asymmetry induces magnetic-dependent charge-to-spin conversion that removes this restriction. Here, we achieved a large enhancement of magnetic-dependent charge-to-spin conversion by clarifying its mechanism. Through layer thickness dependence of the conversion efficiency, we revealed a coexistence of interfacial and bulk contributions to the magnetic-dependent charge-to-spin conversion. Moreover, the interfacial contribution to charge-to-spin conversion is found to be dominant and can be controlled via interfacial band engineering. The efficiency of charge-to-spin conversion in ferromagnet was found to be an order larger than that of other materials with reduced symmetry.

scholarly journals High-Performance Mg3Sb2-xBix Thermoelectrics: Progress and Perspective

Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-22 ◽  
Author(s):  
Airan Li ◽  
Chenguang Fu ◽  
Xinbing Zhao ◽  
Tiejun Zhu
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Low Cost ◽  
Successful Implementation ◽  
Low Grade ◽  
Structure Property ◽  
Promising Alternative ◽  
Band Engineering ◽  
Device Applications ◽  
Boundary Modification

Since the first successful implementation of n-type doping, low-cost Mg3Sb2-xBix alloys have been rapidly developed as excellent thermoelectric materials in recent years. An average figure of merit zT above unity over the temperature range 300–700 K makes this new system become a promising alternative to the commercially used n-type Bi2Te3-xSex alloys for either refrigeration or low-grade heat power generation near room temperature. In this review, with the structure-property-application relationship as the mainline, we first discuss how the crystallographic, electronic, and phononic structures lay the foundation of the high thermoelectric performance. Then, optimization strategies, including the physical aspects of band engineering with Sb/Bi alloying and carrier scattering mechanism with grain boundary modification and the chemical aspects of Mg defects and aliovalent doping, are extensively reviewed. Mainstream directions targeting the improvement of zT near room temperature are outlined. Finally, device applications and related engineering issues are discussed. We hope this review could help to promote the understanding and future developments of low-cost Mg3Sb2-xBix alloys for practical thermoelectric applications.

Enabling Technology Based on Leaky-Mode Resonance Effects in Periodic Films

2007 ◽  
Vol 1054 ◽  
Author(s):  
Robert Magnusson ◽  
Mehrdad Shokooh-Saremi ◽  
Kyu J. Lee ◽  
Debra Wawro
Keyword(s):  
Physical Properties ◽  
Layered Materials ◽  
Leaky Mode ◽  
Enabling Technology ◽  
Photonic Device ◽  
Resonance Effects ◽  
Leaky Modes ◽  
Device Applications

ABSTRACTThe physical properties of resonant leaky modes in periodically patterned layered materials are summarized. Representative examples of photonic device applications including filters, polarizers, wideband reflectors, tunable elements, and biosensors are discussed.

TEM and cathodoluminescence of precipitates in II-VI semiconductors

1988 ◽  
Vol 46 ◽  
pp. 488-489
Author(s):  
Joanna L. Batstone
Keyword(s):  
Crystal Growth ◽  
Band Gap ◽  
Local Strain ◽  
Wide Band ◽  
Optoelectronic Device ◽  
Wide Band Gap ◽  
Bulk Crystal Growth ◽  
Transmission Electron ◽  
Device Applications ◽  
Stoichiometry Control

Interest in II-VI semiconductors centres around optoelectronic device applications. The wide band gap II-VI semiconductors such as ZnS, ZnSe and ZnTe have been used in lasers and electroluminescent displays yielding room temperature blue luminescence. The narrow gap II-VI semiconductors such as CdTe and HgxCd1-x Te are currently used for infrared detectors, where the band gap can be varied continuously by changing the alloy composition x.Two major sources of precipitation can be identified in II-VI materials; (i) dopant introduction leading to local variations in concentration and subsequent precipitation and (ii) Te precipitation in ZnTe, CdTe and HgCdTe due to native point defects which arise from problems associated with stoichiometry control during crystal growth. Precipitation is observed in both bulk crystal growth and epitaxial growth and is frequently associated with segregation and precipitation at dislocations and grain boundaries. Precipitation has been observed using transmission electron microscopy (TEM) which is sensitive to local strain fields around inclusions.

Defects in β-SiC thin films grown on α-SiC substrates

1988 ◽  
Vol 46 ◽  
pp. 568-569
Author(s):  
Karren L. More
Keyword(s):  
Thin Films ◽  
Semiconductor Device ◽  
Lattice Mismatch ◽  
Chemical Vapor ◽  
Substrate Material ◽  
Growth Interface ◽  
Si Substrates ◽  
Thermal Expansion Coefficients ◽  
Device Applications ◽  
Expansion Coefficients

Beta-SiC is an ideal candidate material for use in semiconductor device applications. Currently, monocrystalline β-SiC thin films are epitaxially grown on {100} Si substrates by chemical vapor deposition (CVD). These films, however, contain a high density of defects such as stacking faults, microtwins, and antiphase boundaries (APBs) as a result of the 20% lattice mismatch across the growth interface and an 8% difference in thermal expansion coefficients between Si and SiC. An ideal substrate material for the growth of β-SiC is α-SiC. Unfortunately, high purity, bulk α-SiC single crystals are very difficult to grow. The major source of SiC suitable for use as a substrate material is the random growth of {0001} 6H α-SiC crystals in an Acheson furnace used to make SiC grit for abrasive applications. To prepare clean, atomically smooth surfaces, the substrates are oxidized at 1473 K in flowing 02 for 1.5 h which removes ∽50 nm of the as-grown surface. The natural {0001} surface can terminate as either a Si (0001) layer or as a C (0001) layer.

Strain measurement in In0.2Ga0.8As/GaAs quantum wires by convergent beam electron diffraction

1995 ◽  
Vol 53 ◽  
pp. 444-445
Author(s):  
S. Hillyard ◽  
Y.-P. Chen ◽  
J.D. Reed ◽  
W.J. Schaff ◽  
L.F. Eastman ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Semiconductor Lasers ◽  
Quantum Wire ◽  
Quantum Wires ◽  
Convergent Beam Electron Diffraction ◽  
Zero Order ◽  
Beam Electron ◽  
Local Lattice ◽  
Device Applications ◽  
Convergent Beam

The positions of high-order Laue zone (HOLZ) lines in the zero order disc of convergent beam electron diffraction (CBED) patterns are extremely sensitive to local lattice parameters. With proper care, these can be measured to a level of one part in 104 in nanometer sized areas. Recent upgrades to the Cornell UHV STEM have made energy filtered CBED possible with a slow scan CCD, and this technique has been applied to the measurement of strain in In0.2Ga0.8 As wires.Semiconductor quantum wire structures have attracted much interest for potential device applications. For example, semiconductor lasers with quantum wires should exhibit an improvement in performance over quantum well counterparts. Strained quantum wires are expected to have even better performance. However, not much is known about the true behavior of strain in actual structures, a parameter critical to their performance.

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