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.

Optimization of postproduction heat treatment for plastic solar cells

Abstract: We present this detailed study of a postproduction heat treatment of flexible organic solar cells based on regio-regular (RR) P3HT:PCBM composite in a wide temperature range from 75°C to 150°C. The efficiency of the photovoltaic device was significantly improved by postproduction heat treatment and both optimal annealing temperature and time dependencies were determined. Optimized parameters yielded >3% efficiency for devices on glass substrates and, using these optimized parameters, an efficiency of >2% was found for devices fabricated on flexible substrates. The optimal phase separation of PCBM and RR-P3HT into bi-continuous network structure occurs within a very short period of time and are very stable. We found that optimal concentration of PCBM in a RR-P3HT matrix is rather low, only 34 w.%. We show the performance of plastic solar cells fabricated on flexible substrates (ITO coated PET) using these optimized heat treatment parameters.

Evolution of superconductivity in Ca doped C60 prepared from azide. Low-field microwave absorption and ESR

Abstract: Superconducting (SC) behavior of Ca doped C 60 prepared by calcium azide thermal decomposition is studied by low-field signal (LFS) microwave absorption and conventional ESR. SC phase is obtained for the sample prepared with nominal composition of Ca 6 C 60 and its volume fraction is significantly enlarged by annealing at 350–400°C for 2 h. It is suggested that the SC compound may have two SC phases with slightly different transition temperatures, T C1 (8.2–8.4 K) and T C2 (8.7–8.8 K). The SC 2 phase with higher T C2 is degraded by annealing at 450–500°C and converts to SC 1 . Degradation of SC 2 at high temperature is interpreted to be caused either by (1) thermal reaction of some intercalated Ca with quartz glass and/or (2) dissociation of (CaN) y or N y clusters in the octahedral sites of the Ca 5 (CaN) y C 60 or Ca 5 N y C 60 lattice.

Doping effects of higher fullerene in conducting polymer

Abstract: Doping effects of higher fullerenes such as C 70 on electrical and optical properties of conducting polymers such as poly(3-alkylthiophene), poly(2,5-dialkoxy-p-phenylene vinylene) and poly(9,9-dialkylfluorene) have been studied and compared with those by C 60 doping. Fluorescence intensity was quenched and photoconductivity was enhanced upon doping of higher fullerenes in the conducting polymers just as the case of C 60 doping. However, there also exist differences in detailed aspects in quenching of photoluminescence and enhancement of photoconductivity between C 60 doping and higher fullerenes dopings. These results are interpreted by taking into account the electronic energy states of C 60 and higher fullerenes.

Electric Field Effect in Atomically Thin Carbon Films

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.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

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。

Carbon Nanotubes--the Route Toward Applications

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.