85 research outputs found
Chalcogen Assisted Enhanced Atomic Orbital Interaction at TMDs - Metal Interface & Chalcogen Passivation of TMD Channel For Overall Performance Boost of 2D TMD FETs
Metal-semiconductor interface is a bottleneck for efficient transport of
charge carriers through Transition Metal Dichalcogenide (TMD) based
field-effect transistors (FETs). Injection of charge carriers across such
interfaces is mostly limited by Schottky barrier at the contacts which must be
reduced to achieve highly efficient contacts for carrier injection into the
channel. Here we introduce a universal approach involving dry chemistry to
enhance atomic orbital interaction between various TMDs (MoS2, WS2, MoSe2 and
WSe2) & metal contacts has been experimentally demonstrated. Quantum chemistry
between TMDs, Chalcogens and metals has been explored using detailed atomistic
(DFT & NEGF) simulations, which is then verified using Raman, PL and XPS
investigations. Atomistic investigations revealed lower contact resistance due
to enhanced orbital interaction and unique physics of charge sharing between
constituent atoms in TMDs with introduced Chalcogen atoms which is subsequently
validated through experiments. Besides contact engineering, which lowered
contact resistance by 72, 86, 1.8, 13 times in MoS2, WS2, MoSe2 and WSe2
respectively, a novel approach to cure / passivate dangling bonds present at
the 2D TMD channel surface has been demonstrated. While the contact engineering
improved the ON-state performance (ION, gm, mobility and RON) of 2D TMD FETs by
orders of magnitude, Chalcogen based channel passivation was found to improve
gate control (IOFF, SS, & VTH) significantly. This resulted in an overall
performance boost. The engineered TMD FETs were shown to have performance on
par with best reported till date
Drought yield index to select high yielding rice lines under different drought stress severities
BACKGROUND Drought is the most severe abiotic stress reducing rice yield in rainfed drought prone ecosystems. Variation in intensity and severity of drought from season to season and place to place requires cultivation of rice varieties with different level of drought tolerance in different areas. Multi environment evaluation of breeding lines helps breeder to identify appropriate genotypes for areas prone to similar level of drought stress. From a set of 129 advanced rice (Oryza sativa L.) breeding lines evaluated under rainfed drought-prone situations at three locations in eastern India from 2005 to 2007, a subset of 39 genotypes that were tested for two or more years was selected to develop a drought yield index (DYI) and mean yield index (MYI) based on yield under irrigated, moderate and severe reproductive-stage drought stress to help breeders select appropriate genotypes for different environments. RESULTS ARB 8 and IR55419-04 recorded the highest drought yield index (DYI) and are identified as the best drought-tolerant lines. The proposed DYI provides a more effective assessment as it is calculated after accounting for a significant genotype x stress-level interaction across environments. For rainfed areas with variable frequency of drought occurrence, Mean yield index (MYI) along with deviation in performance of genotypes from currently cultivated popular varieties in all situations helps to select genotypes with a superior performance across irrigated, moderate and severe reproductive-stage drought situations. IR74371-70-1-1 and DGI 75 are the two genotypes identified to have shown a superior performance over IR64 and MTU1010 under all situations. CONCLUSION For highly drought-prone areas, a combination of DYI with deviation in performance of genotypes under irrigated situations can enable breeders to select genotypes with no reduction in yield under favorable environments compared with currently cultivated varieties. For rainfed areas with variable frequency of drought stress, use of MYI together with deviation in performance of genotypes under different situations as compared to presently cultivated varieties will help breeders to select genotypes with superior performance under all situations.Anitha Raman, Satish Verulkar B, Nimai Mandal P, Mukund Variar, V Shukla D, J Dwivedi L, B Singh N, O Singh N, Padmini Swain, Ashutosh Mall K, S Robin, R Chandrababu, Abhinav Jain, Tilatoo Ram, Shailaja Hittalmani, Stephan Haefele, Hans-Peter Piepho, and Arvind Kuma
Emerging giants : China and India "Chindia"
The twenty-first century looks upon China and India as emerging economic and political champions; very different from the portrayal of the twentieth century which anticipated United States, the Soviet Union, Japan and North Western Europe to be the world's great powers (Drezner, 2007). The central focus of this research is to establish, why China and India would cooperate rather than rival one another despite a history of disputed borders and an element of mistrust? The main strategic purpose of both China and India is driven by the desire to seek regional and then global strategic dominance which makes all other objectives subservient to that.Master of Science (International Relations
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