| 41. |
- Zou, Haiyang, et al.
(författare)
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Dramatically Enhanced Broadband Photodetection by Dual Inversion Layers and Fowler-Nordheim Tunneling
- 2019
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 13:2, s. 2289-2297
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Tidskriftsartikel (refereegranskat)abstract
- Silicon photonics is now widely accepted as a key technology in a variety of systems. But owing to material limitations, now it is challenging to greatly improve the performance after decades of development. Here, we show a high-performance broadband photodetector with significantly enhanced sensitivity and responsivity operating over a wide wavelength range of light from near-ultraviolet to near-infrared at low power consumption. The specially designed textured top ceiling electrode works effectively as an antireflection layer to greatly improve the absorption of near-infrared light, thereby overcoming the absorption limitation of near-infrared light. Instead of the conventional p-n junction and p-intrinsic-n junction, we introduce a similar to 15 nm thick alumina insulator layer between a p-type Si substrate and n-type ZnO nanowire (NW) arrays, which significantly enhances the charge carrier separation and collection efficiency. The photosensing responsivity and sensitivity are found to be nearly 1 order of magnitude higher than that of a reference device of p-Si/n-ZnO NW arrays, significantly higher than the commercial silicon photodiodes as well. The light-induced charge carriers flow across the appropriate thickness of insulator layer via the quantum mechanical Fowler-Nordheim tunneling mechanism. By virtue of the piezo-phototronic effect, the charge density at the interfaces can be tuned to alter the energy bands and the potential barrier distance for tunneling. Additionally, along with the use of incident light of different wavelengths, the influence of the insulator layer on the transport of electrons and holes separately is further investigated. The demonstrated concepts and study would lead to sensitivity improvement, quality enhancement of data transfer, decrease of power consumption, and cost reduction of silicon photonics.
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| 42. |
- Adcox, K, et al.
(författare)
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Formation of dense partonic matter in relativistic nucleus-nucleus collisions at RHIC: Experimental evaluation by the PHENIX Collaboration
- 2005
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Ingår i: Nuclear Physics, Section A. - : Elsevier BV. - 0375-9474. ; 757:1-2, s. 184-283
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Forskningsöversikt (refereegranskat)abstract
- Extensive experimental data from high-energy nucleus-nucleus collisions were recorded using the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). The comprehensive set of measurements from the first three years of RHIC operation includes charged particle multiplicities, transverse energy, yield ratios and spectra of identified hadrons in a wide range of transverse momenta (PT), elliptic flow, two-particle correlations, nonstatistical fluctuations, and suppression of particle production at high PT. The results are examined with an emphasis on implications for the formation of a new state of dense matter. We find that the state of matter created at RHIC cannot be described in terms of ordinary color neutral hadrons.
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| 43. |
- Albrecht, Stefano V., et al.
(författare)
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Reports on the 2015 AAAI Workshop Series
- 2015
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Ingår i: The AI Magazine. - : Wiley. - 0738-4602 .- 2371-9621. ; 36:2, s. 90-101
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Tidskriftsartikel (refereegranskat)abstract
- AAAI's 2015 Workshop Program was held Sunday and Monday, January 25-26, 2015, at the Hyatt Regency Austin Hotel in Austin, Texas, USA. The AAAI-15 workshop program included 16 workshops covering a wide range of topics in artificial intelligence. Most workshops were held on a single day. The titles of the workshops included Algorithm Configuration; Artificial Intelligence and Ethics; Artificial Intelligence Applied to Assistive Technologies and Smart Environments; Artificial Intelligence for Cities; Artificial Intelligence for Transportation: Advice, Inter-activity, and Actor Modeling; Beyond the Turing Test; Computational Sustainability; Computer Poker and Imperfect Information; Incentive and Trust in E-Communities; Knowledge, Skill, and Behavior Transfer in Autonomous Robots; Learning for General Competency in Video Games; Multiagent Interaction without Prior Coordination; Planning, Search, and Optimization; Scholarly Big Data: AI Perspectives, Challenges, and Ideas; Trajectory-Based Behaviour Analytics; and World Wide Web and Public Health Intelligence.
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| 44. |
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| 45. |
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| 46. |
- Chi, Chaodan, et al.
(författare)
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Molecular beam epitaxy growth of GaSb1-xBix without rotation
- 2019
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Ingår i: Vacuum. - : Elsevier BV. - 0042-207X. ; 168
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Tidskriftsartikel (refereegranskat)abstract
- GaSb1-xBix thin film was grown on a 2 inch GaSb substrate by molecular beam epitaxy (MBE) without substrate rotation. Bi composition is found to vary from 2.76% to 3.98% across the wafer. The distribution of Bi content is mainly determined by spatial non-uniformity of Sb/Ga flux ratio, while Bi flux has slightly influence. Ostwald ripening process is confirmed to be reason for bigger Bi droplets via Bi surface diffusion. With the increase of Sb/Ga flux ratio, Ostwald ripening process is suppressed. At high Bi flux, excess Ga atoms accumulate on surface and form droplets.
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| 47. |
- Chi, Chaodan, et al.
(författare)
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Si-based InGaAs photodetectors on heterogeneous integrated substrate
- 2021
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Ingår i: Science China: Physics, Mechanics and Astronomy. - : Springer Science and Business Media LLC. - 1674-7348 .- 1869-1927. ; 64:6
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, InGaAs p-i-n photodetectors (PDs) on an InP/SiO2/Si (InPOI) substrate fabricated by ion-slicing technology are demonstrated and compared with the identical device on a commercial InP substrate. The quality of epitaxial layers on the InPOI substrate is similar to that on the InP substrate. The photo responsivities of both devices measured at 1.55 µm are comparable, which are about 0.808–0.828 A W−1. Although the dark current of PD on the InPOI substrate is twice as high as that of PD on the InP substrate at 300 K, the peak detectivities of both PDs are comparable. In general, the overall performance of the InPOI-based PD is comparable to the InP-based PD, demonstrating that the ion-slicing technology is a promising route to enable the high-quality Si-based InP platform for the full photonic integration on a Si substrate.
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| 48. |
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| 49. |
- Hao, Zhengming, et al.
(författare)
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Converting n-Alkanol to Conjugated Polyenal on Cu(110) Surface at Mild Temperature
- 2022
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Ingår i: The Journal of Physical Chemistry Letters. - : AMER CHEMICAL SOC. - 1948-7185. ; 13:14, s. 3276-3282
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Tidskriftsartikel (refereegranskat)abstract
- Achieving C(sp(3))-H activation at a mild temperature is of great importance from both scientific and technologic points of view. Herein, on the basis of the on-surface synthesis strategy, we report the significant reduction of the C(sp(3))-H activation barrier, which results in the full C(sp(3))-H to C(sp(2))-H transformation of n-alkanol (octacosan-1-ol) at a mild temperature as low as 350 K on the Cu(110) surface, yielding the conjugated polyenal (octacosa-tridecaenal) as the final product. The reaction mechanism is revealed by the combined scanning tunneling microscope, density functional theory, and synchrotron radiation photoemission spectroscopy.
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| 50. |
- Hao, Zhengming, et al.
(författare)
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From n-alkane to polyacetylene on Cu (110): Linkage modulation in chain growth
- 2022
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Ingår i: Science in China Series B. - : SCIENCE PRESS. - 1674-7291 .- 1869-1870. ; 65:4, s. 733-739
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Tidskriftsartikel (refereegranskat)abstract
- Direct coupling or transformation of inert alkanes based on the selective C-H activation is of great importance for both chemistry and chemical engineering. Here, we report the coupling of polyenes that are transformed from n-dotriacontane (n-C32H66) through on-surface cascade dehydrogenation on Cu (110) surface, leading to the formation of polyacetylene (PA). Three distinct linkages have been resolved by scanning tunneling microscope (STM) and noncontact atomic force microscope (nc-AFM). Apart from the alpha-type linkage which is the stemless coupling of the terminal C-C double bond in trans-configuration, beta- and gamma-type linkages appear as knots or defects which are, in fact, the C-C couplings in cis-configurations. Interestingly, the "defects" can be effectively suppressed by adjusting the surface coverage, thus making it of general interest for uniform structure modulation.
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