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Anvar A. Zakhidov

Bio: Anvar A. Zakhidov is an academic researcher from University of Texas at Dallas. The author has contributed to research in topics: Perovskite (structure) & Carbon nanotube. The author has an hindex of 63, co-authored 417 publications receiving 27644 citations. Previous affiliations of Anvar A. Zakhidov include University of Texas System & Business International Corporation.


Papers
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01 Dec 2005
TL;DR: In this paper, the main technical objective is the controlled reduction of infrared emissivity, since objects of interest are generally hotter than their surroundings, and the tunability of emissivities is made possible by electrochromics, which is becoming a common technology that is used in self-dimming rear view mirrors in automobiles.
Abstract: : The goal of this research program was to create a technology for artificially programmable infrared emissivity of surfaces. As an example, this would permit a vehicle, or a person to blend into its surroundings, and become invisible to an infrared camera. A great deal has been accomplished in this research program, that will help convert this technology into a practical reality. The main technical objective is the controlled reduction of infrared emissivity. An emissivity reduction not an increase is desired, since objects of interest are generally hotter than their surroundings. The tunability of emissivity is made possible by electrochromics. Today, electrochromics is becoming a common technology that is used, for example, in self-dimming rear view mirrors in automobiles. Electrochromic materials change their color by undergoing an electronic transition of some form. In the most common type the electronic transformation is induced electro-chemically in special polymeric materials. In effect this is a type of electrochemical doping, with the material thereby undergoing a transition from an insulator to a metal, with the corresponding changes in color.

2 citations

Journal ArticleDOI
TL;DR: In this paper, high-pressure fluorination of multi-walled carbon nanotubes (MWNTs) sheet was performed at room temperature to increase the electrical conductivity of MWNTs.
Abstract: High-pressure fluorination of multi-walled carbon nanotubes (MWNTs) sheet was performed at room temperature. This fluorine treatment increases the electrical conductivity of MWNTs sheet. In addition, low-temperature conductivity measurement data gives a good fit to variable-range hopping (VRH) model. Thus, VRH model was adopted to study and understand the increase in electrical conductivity. Estimation of the degree of disorder from the experimental data and VRH model indicate that degree of disorder of fluorinated multi-walled carbon nanotubes (FMWNTs) is higher than that of MWNTs. Higher degree of disorder of FMWNTs sheet substantiate the increase in electrical conductivity when compared to MWNTs. Scanning Electron Microscopy (SEM) and Raman analysis shows that change in structural disorder of FMWNTs network. Effect of fluorination on activation energy was also studied. The activation energy reduces with lower temperatures. The estimated values of temperature coefficient of resistance also show the increase in degree of disorder of FMWNTs. The change in electrical properties of FMWNTs is a much-needed requirement in the application of nano-electronics.

2 citations

Posted Content
TL;DR: In this paper, the authors employed a CsPbBr3 perovskite host and a novel ionic iridium complex guest along with a polyelectrolyte to demonstrate efficient light emitting electrochemical cells (PeLECs).
Abstract: Perovskite light emitting devices have drawn considerable attention for their favorable optoelectronic properties. High carrier mobilities make perovskites excellent candidates as host materials in electroluminescent devices. To achieve high performance in a simple single layer device, we employed a CsPbBr3 perovskite host and a novel ionic iridium complex guest along with a polyelectrolyte to demonstrate efficient light emitting electrochemical cells (PeLECs). For an optimal guest/host blend, 10600 cd/m2 luminance at 11.6 cd/A and 9.04 Lm/W are achieved at 4.1 V. These devices showed voltage-dependent electroluminescence color proceeding from orange-red to green, facilitated by the reconfigurable ionic materials blend. Optimized devices exhibited stable operation under constant current driving, maintaining >630 cd/m2 emission for 40 h. Our rationally-designed ionic guest at an optimal concentration of the host produced efficient (>90%) Forster energy transfer and improved thin film morphological for high performance PeLEC operation enabled by ionic migration to interfaces

2 citations

Journal ArticleDOI
TL;DR: In this article, the authors investigated hydrogen uptake effects on the properties of metallic K 3 C 60 by means of ESR and superconductivity measurements and showed that superconductivities are not influenced by hydrogen uptake.

2 citations

Journal ArticleDOI
TL;DR: In this paper , the gate voltage of a top carbon nanotubes (CNT) cathode in ionic liquid by changing gate voltage (V g) tunes the Fermi level of CNT by electrical double layer charging and causes lowering of the barrier at C60/C70 electron transport layer (ETL).
Abstract: Metallic cathodes are one of reasons for instability in perovskite solar cells due to reaction with halogens I−, Br−, and it is desirable to have stable carbon-based cathodes, particularly carbon nanotubes (CNTs), and transport layers such as C60/C70. In this work, we show that gating of such top CNT cathode in ionic liquid by changing gate voltage (V g) tunes the Fermi level of CNT by electrical double layer charging and causes lowering of the barrier at C60/C70 electron transport layer (ETL). Moreover, at higher V g the ions further propagate into fullerene ETL by electrochemical n-doping, which increases dramatically performance by further raising mostly two parameters: short-circuit current and fill factor, resulting in solar cell efficiency growth from 3% to 11%. Surprisingly, open-circuit voltage (V oc) is not sensitive to V g in the perovskite solar cells, on the contrary to strongly enhanced V oc in ionically gated organic solar cells, where it is the main effect for ionic gating. This insensitivity of V oc to lowering of the work function of CNT electrode is a clear indication that V oc in the perovskite solar cell is determined by inner p-i-n junction formation in the perovskite layer itself.

2 citations


Cited by
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Journal ArticleDOI
22 Oct 2004-Science
TL;DR: Monocrystalline graphitic films are found to be a two-dimensional semimetal with a tiny overlap between valence and conductance bands and they exhibit a strong ambipolar electric field effect.
Abstract: We describe monocrystalline graphitic films, which are a few atoms thick but are nonetheless stable under ambient conditions, metallic, and of remarkably high quality. The films are found to be a two-dimensional semimetal with a tiny overlap between valence and conductance bands, and they exhibit a strong ambipolar electric field effect such that electrons and holes in concentrations up to 10 13 per square centimeter and with room-temperature mobilities of ∼10,000 square centimeters per volt-second can be induced by applying gate voltage.

55,532 citations

28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal ArticleDOI
02 Aug 2002-Science
TL;DR: Many potential applications have been proposed for carbon nanotubes, including conductive and high-strength composites; energy storage and energy conversion devices; sensors; field emission displays and radiation sources; hydrogen storage media; and nanometer-sized semiconductor devices, probes, and interconnects.
Abstract: Many potential applications have been proposed for carbon nanotubes, including conductive and high-strength composites; energy storage and energy conversion devices; sensors; field emission displays and radiation sources; hydrogen storage media; and nanometer-sized semiconductor devices, probes, and interconnects. Some of these applications are now realized in products. Others are demonstrated in early to advanced devices, and one, hydrogen storage, is clouded by controversy. Nanotube cost, polydispersity in nanotube type, and limitations in processing and assembly methods are important barriers for some applications of single-walled nanotubes.

9,693 citations