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Saturation velocity

About: Saturation velocity is a(n) research topic. Over the lifetime, 1308 publication(s) have been published within this topic receiving 28650 citation(s). more


Journal ArticleDOI: 10.1016/S0921-5107(00)00604-8
David C. Look1Institutions (1)
Abstract: Wurtzitic ZnO is a wide-bandgap (3.437 eV at 2 K) semiconductor which has many applications, such as piezoelectric transducers, varistors, phosphors, and transparent conducting films. Most of these applications require only polycrystalline material; however, recent successes in producing large-area single crystals have opened up the possibility of producing blue and UV light emitters, and high-temperature, high-power transistors. The main advantages of ZnO as a light emitter are its large exciton binding energy (60 meV), and the existence of well-developed bulk and epitaxial growth processes; for electronic applications, its attractiveness lies in having high breakdown strength and high saturation velocity. Optical UV lasing, at both low and high temperatures, has already been demonstrated, although efficient electrical lasing must await the further development of good, p-type material. ZnO is also much more resistant to radiation damage than are other common semiconductor materials, such as Si, GaAs, CdS, and even GaN; thus, it should be useful for space applications. more

Topics: Saturation velocity (53%), Semiconductor (52%), Lasing threshold (51%)

2,485 Citations

Journal ArticleDOI: 10.1038/NNANO.2008.268
Inanc Meric1, Melinda Y. Han1, Andrea Young1, Barbaros Özyilmaz1  +2 moreInstitutions (1)
Abstract: The first observation of saturating transistor characteristics in a graphene field-effect transistor is reported. The saturation velocity is attributed to scattering by interfacial phonons in the silicon dioxide layer supporting the graphene channels. These results demonstrate the feasibility of graphene devices for analogue and radio-frequency circuit applications without the need for bandgap engineering. more

Topics: Graphene nanoribbons (66%), Graphene (59%), Saturation velocity (58%) more

1,482 Citations

Journal ArticleDOI: 10.1038/NATURE09979
Yanqing Wu1, Yu-Ming Lin1, Ageeth A. Bol1, Keith A. Jenkins1  +4 moreInstitutions (1)
07 Apr 2011-Nature
Abstract: Owing to its high carrier mobility and saturation velocity, graphene has attracted enormous attention in recent years1, 2, 3, 4, 5. In particular, high-performance graphene transistors for radio-frequency (r.f.) applications are of great interest6, 7, 8, 9, 10, 11, 12, 13. Synthesis of large-scale graphene sheets of high quality and at low cost has been demonstrated using chemical vapour deposition (CVD) methods14. However, very few studies have been performed on the scaling behaviour of transistors made from CVD graphene for r.f. applications, which hold great potential for commercialization. Here we report the systematic study of top-gated CVD-graphene r.f. transistors with gate lengths scaled down to 40 nm, the shortest gate length demonstrated on graphene r.f. devices. The CVD graphene was grown on copper film and transferred to a wafer of diamond-like carbon. Cut-off frequencies as high as 155 GHz have been obtained for the 40-nm transistors, and the cut-off frequency was found to scale as 1/(gate length). Furthermore, we studied graphene r.f. transistors at cryogenic temperatures. Unlike conventional semiconductor devices where low-temperature performance is hampered by carrier freeze-out effects, the r.f. performance of our graphene devices exhibits little temperature dependence down to 4.3 K, providing a much larger operation window than is available for conventional devices. more

Topics: Graphene nanoribbons (68%), Graphene (59%), Saturation velocity (58%) more

840 Citations

Journal ArticleDOI: 10.1016/S0379-6779(02)00398-3
Norbert Karl1Institutions (1)
13 Mar 2003-Synthetic Metals
Abstract: To understand charge carrier transport in organic semiconductors the magnitude and anisotropy, as well as the temperature and eventual electric field dependence of the electron and of the hole mobility are fundamental parameters. A number of technical applications require high mobilities. A brief review is given on different experimental methods that can either directly measure charge carrier mobilities, or at least lead to an estimate. For high purity single crystals, a steep increase of mobilities towards low temperature with the consequence of nonlinear transport and final velocity saturation at elevated electric fields has been found and traced back to temperature-dependent electron and hole masses approaching the free electron mass at low temperature. This, and additional recent reports in literature on ultrahigh mobilities—with a number of exciting consequences, such as integer and fractional quantum Hall effect and even superconductivity in such materials as anthracene, tetracene, pentacene, and C60—are clear indications of band transport. With rising temperature electron–phonon coupling, and therefore the effective masses, increase and coherent band transport is gradually destroyed; polaron-hopping transport evolves as a parallel channel and dominates at sufficiently high temperature. For crystals with orientational disorder of the molecules band transport is precluded. more

Topics: Saturation velocity (61%), Charge carrier (60%), Electron mobility (59%) more

557 Citations

Journal ArticleDOI: 10.1109/T-ED.1975.18267
Abstract: The drift velocity of electrons and holes in silicon has been measured in a large range of the electric fields (from 3 . 102to 6 . 104V/cm) at temperatures up to 430 K. The experimental data have been fitted with a simple formula for the temperatures of interest. The mean square deviation was in all cases less than 3.8 percent. A more general formula has also been derived which allows to obtain by extrapolation drift velocity data at any temperature and electric field. more

Topics: Drift velocity (71%), Saturation velocity (61%), Electric field (56%) more

528 Citations

No. of papers in the topic in previous years

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Topic's top 5 most impactful authors

Vijay K. Arora

23 papers, 303 citations

Razali Ismail

21 papers, 181 citations

Michael Shur

16 papers, 470 citations

Gerard Ghibaudo

13 papers, 199 citations

Vijay K. Arora

10 papers, 82 citations

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