Debesh R. Roy

Bio: Debesh R. Roy is an academic researcher from Sardar Vallabhbhai National Institute of Technology, Surat. The author has contributed to research in topics: Density functional theory & Thermoelectric effect. The author has an hindex of 6, co-authored 40 publications receiving 162 citations. Previous affiliations of Debesh R. Roy include University of Bremen.

Structure, bonding, stability, electronic, thermodynamic and thermoelectric properties of six different phases of indium nitride

Abstract: Density functional investigation is carried out on the structure and bonding, stability, electronic, thermodynamic and thermoelectric properties on the six different phases of indium nitride. In addition to the monolayer hexagonal, zinc blende, wurtzite and rock salt, two more new possible phases, viz. caesium chloride and nickel arsenide, are also explored. The calculated crystal parameters for all six phases are compared with available experimental and theoretical values. Band structure and density of states are predicted for understanding their behaviour in metal–insulator–semiconductor domains as well as the contribution of their different atomic orbitals around the valence and conduction band edges. Phonon dispersion curves are generated to understand the dynamical stability of the considered indium nitride phases. Further, a detail comparative study is performed on various thermodynamic and thermoelectric properties of the dynamically stable indium nitride phases. An electron density contour is also generated for the stable phases to understand the nature bonding between indium and nitride in those phases.

h -CaS and h -CaSe nanosheets in Ca X ( X = O, S, Se and Te) series: promising thermoelectric materials under DFT investigation

Abstract: The present work reports systematic study of a series of calcium chalcogenides CaX (X = O, S, Se and Te) in the architecture of rock-salt and hexagonal monolayer phases. Using first principle investigation within density functional theory (DFT) framework, we have computed the equilibrium structure and phonon dispersion curves for the dynamic stability, which follows the calculation of electronic properties like electronic band structure and projected density of state for the considered chalcogenide series. Furthermore, the thermoelectric properties such as thermal and electrical conductivities, Seebeck coefficient (S) and figure of merit (ZT) of the considered compounds are computed using the semi-classical Boltzmann transport equations (BTE). The present work reports the monolayer calcium chalcogenides as potential candidate for thermoelectric applications.

First-Principles Calculations of SiBi Nanosheets as Sensors for Oxygen-Containing Gases

Abstract: First-principles calculations are performed to investigate the approachable application of a two-dimensional SiBi nanosheet as an oxygen-containing gas (OCG) sensor material. Through detailed analy...

Black Phosphorus Field-effect Transistors

Abstract: Two-dimensional crystals have emerged as a class of materials that may impact future electronic technologies. Experimentally identifying and characterizing new functional two-dimensional materials is challenging, but also potentially rewarding. Here, we fabricate field-effect transistors based on few-layer black phosphorus crystals with thickness down to a few nanometres. Reliable transistor performance is achieved at room temperature in samples thinner than 7.5 nm, with drain current modulation on the order of 10(5) and well-developed current saturation in the I-V characteristics. The charge-carrier mobility is found to be thickness-dependent, with the highest values up to ∼ 1,000 cm(2) V(-1) s(-1) obtained for a thickness of ∼ 10 nm. Our results demonstrate the potential of black phosphorus thin crystals as a new two-dimensional material for applications in nanoelectronic devices.

Green synthesis: Photocatalytic degradation of textile dyes using metal and metal oxide nanoparticles-latest trends and advancements

Abstract: The balance between economic development and environmental damage is also evident in the problem of pollution and waste management. Increased economic activity, mainly in industrial countries, has ...

Endohedrally Doped Cage Clusters

Abstract: The discovery of carbon fullerene cages and their solids opened a new avenue to build materials from stable cage clusters as “artificial atoms” or “superatoms” instead of atoms. However, cage clust...

Monolayer II-VI semiconductors: A first-principles prediction

Abstract: Hui Zheng,1 Xian-Bin Li,1,* Nian-Ke Chen,1 Sheng-Yi Xie,1 Wei Quan Tian,1,2 Yuanping Chen,3 Hong Xia,1 S. B. Zhang,1,4,† and Hong-Bo Sun1,‡ 1State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China 2Institute of Theoretical Chemistry, Jilin University, Changchun 130012, China 3Laboratory for Quantum Engineering and Micro-Nano Energy Technology, Xiangtan University, Xiangtan 411105, China 4Department of Physics, Applied Physics, & Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, USA (Received 11 January 2015; revised manuscript received 14 May 2015; published 21 September 2015)

Biosynthesis of Flower-Shaped CuO Nanostructures and Their Photocatalytic and Antibacterial Activities

Abstract: Copper oxide nanoflowers (CuO-NFs) have been synthesized through a novel green route using Tulsi leaves-extracted eugenol (4-allyl-2-methoxyphenol) as reducing agent. Characterizations results reveal the growth of crystalline single-phase CuO-NFs with monoclinic structure. The prepared CuO-NFs can effectively degrade methylene blue with 90% efficiency. They also show strong barrier against E. coli (27 ± 2 mm) at the concentration of 100 µg mL−1, while at the concentration of 25 µg mL−1 weak barrier has been found against all examined bacterial organisms. The results provide important evidence that CuO-NFs have sustainable performance in methylene blue degradation as well as bacterial organisms.