Soumendu Datta

Bio: Soumendu Datta is an academic researcher from S.N. Bose National Centre for Basic Sciences. The author has contributed to research in topics: Cluster (physics) & Density functional theory. The author has an hindex of 15, co-authored 36 publications receiving 1336 citations. Previous affiliations of Soumendu Datta include Bose Corporation & Technical University of Denmark.

Communications: Elementary oxygen electrode reactions in the aprotic Li-air battery

Abstract: We discuss the electrochemical reactions at the oxygen electrode of an aprotic Li-air battery. Using density functional theory to estimate the free energy of intermediates during the discharge and charge of the battery, we introduce a reaction free energy diagram and identify possible origins of the overpotential for both processes. We also address the question of electron conductivity through the Li(2)O(2) electrode and show that in the presence of Li vacancies Li(2)O(2) becomes a conductor.

Computational screening of perovskite metal oxides for optimal solar light capture

Abstract: One of the possible solutions to the world's rapidly increasing energy demand is the development of new photoelectrochemical cells with improved light absorption. This requires development of semiconductor materials which have appropriate bandgaps to absorb a large part of the solar spectrum at the same time as being stable in aqueous environments. Here we demonstrate an efficient, computational screening of relevant oxide and oxynitride materials based on electronic structure calculations resulting in the reduction of a vast space of 5400 different materials to only 15 promising candidates. The screening is based on an efficient and reliable way of calculating semiconductor band gaps. The outcome of the screening includes all already known successful materials of the types investigated plus some new ones which warrant further experimental investigation.

Structure, bonding, and magnetism of cobalt clusters from first-principles calculations

Abstract: The structural, electronic, and magnetic properties of ${\mathrm{Co}}_{n}$ clusters $(n=2--20)$ have been investigated using density functional theory within the pseudopotential plane wave method. An unusual hexagonal growth pattern has been observed in the intermediate size range, $n=15--20$. The cobalt atoms are ferromagnetically ordered and the calculated magnetic moments are found to be higher than that of corresponding hcp bulk value, which are in good agreement with the recent Stern-Gerlach experiments. The average coordination number is found to dominate over the average bond length to determine the effective hybridization and consequently the cluster magnetic moment.

Band-gap variation in Mg- and Cd-doped ZnO nanostructures and molecular clusters

Abstract: We study the effect of doping on band gap in Mg- and Cd-doped zinc oxide nanostructures and molecular clusters. The fabrication of doped nanostructures was carried out via solution route. The lower doping efficiency of Cd than that of Mg has been explained in terms of binding energy. The band gap varied from $3.04\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ in Cd-doped ($9.1\phantom{\rule{0.3em}{0ex}}\mathrm{at.}\phantom{\rule{0.2em}{0ex}}%$ of Cd) nanostructure to $3.99\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ in Mg-doped ($16.8\phantom{\rule{0.3em}{0ex}}\mathrm{at.}\phantom{\rule{0.2em}{0ex}}%$ of Mg) nanostructure. Theoretical analysis using first-principles molecular dynamics techniques on pristine and doped ZnO clusters shows that the energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital exhibits a similar variation as does the band gap in nanostructures with the varying concentration of Mg and Cd.

Density functional theory based screening of ternary alkali-transition metal borohydrides: A computational material design project

Abstract: We present a computational screening study of ternary metal borohydrides for reversible hydrogen storage based on density functional theory. We investigate the stability and decomposition of alloys containing 1 alkali metal atom, Li, Na, or K M1; and 1 alkali, alkaline earth or 3d / 4d transition metal atom M2 plus two to five BH4  groups, i.e., M1M2BH42‐5, using a number of model structures with trigonal, tetrahedral, octahedral, and free coordination of the metal borohydride complexes. Of the over 700 investigated structures, about 20 were predicted to form potentially stable alloys with promising decomposition energies. The M1Al/ Mn/ FeBH44, Li/ NaZnBH43, and Na/ KNi/ CoBH43 alloys are found to be the most promising, followed by selected M1Nb/ RhBH44 alloys. © 2009 American Institute of Physics. DOI: 10.1063/1.3148892

Commentary: The Materials Project: A materials genome approach to accelerating materials innovation

Abstract: Accelerating the discovery of advanced materials is essential for human welfare and sustainable, clean energy. In this paper, we introduce the Materials Project (www.materialsproject.org), a core program of the Materials Genome Initiative that uses high-throughput computing to uncover the properties of all known inorganic materials. This open dataset can be accessed through multiple channels for both interactive exploration and data mining. The Materials Project also seeks to create open-source platforms for developing robust, sophisticated materials analyses. Future efforts will enable users to perform ‘‘rapid-prototyping’’ of new materials in silico, and provide researchers with new avenues for cost-effective, data-driven materials design. © 2013 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.

Perovskites: The Emergence of a New Era for Low-Cost, High-Efficiency Solar Cells

Abstract: Over the last 12 months, we have witnessed an unexpected breakthrough and rapid evolution in the field of emerging photovoltaics, with the realization of highly efficient solid-state hybrid solar cells based on organometal trihalide perovskite absorbers. In this Perspective, the steps that have led to this discovery are discussed, and the future of this rapidly advancing concept have been considered. It is likely that the next few years of solar research will advance this technology to the very highest efficiencies while retaining the very lowest cost and embodied energy. Provided that the stability of the perovskite-based technology can be proven, we will witness the emergence of a contender for ultimately low-cost solar power.

Lithium−Air Battery: Promise and Challenges

Abstract: The lithium−air system captured worldwide attention in 2009 as a possible battery for electric vehicle propulsion applications. If successfully developed, this battery could provide an energy source for electric vehicles rivaling that of gasoline in terms of usable energy density. However, there are numerous scientific and technical challenges that must be overcome if this alluring promise is to turn into reality. The fundamental battery chemistry during discharge is thought to be the electrochemical oxidation of lithium metal at the anode and reduction of oxygen from air at the cathode. With aprotic electrolytes, as used in Li-ion batteries, there is some evidence that the process can be reversed by applying an external potential, i.e., that such a battery can be electrically recharged. This paper summarizes the authors’ view of the promise and challenges facing development of practical Li−air batteries and the current understanding of its chemistry. However, it must be appreciated that this perspective ...

Metal–air batteries: from oxygen reduction electrochemistry to cathode catalysts

Abstract: Because of the remarkably high theoretical energy output, metal–air batteries represent one class of promising power sources for applications in next-generation electronics, electrified transportation and energy storage of smart grids. The most prominent feature of a metal–air battery is the combination of a metal anode with high energy density and an air electrode with open structure to draw cathode active materials (i.e., oxygen) from air. In this critical review, we present the fundamentals and recent advances related to the fields of metal–air batteries, with a focus on the electrochemistry and materials chemistry of air electrodes. The battery electrochemistry and catalytic mechanism of oxygen reduction reactions are discussed on the basis of aqueous and organic electrolytes. Four groups of extensively studied catalysts for the cathode oxygen reduction/evolution are selectively surveyed from materials chemistry to electrode properties and battery application: Pt and Pt-based alloys (e.g., PtAu nanoparticles), carbonaceous materials (e.g., graphene nanosheets), transition-metal oxides (e.g., Mn-based spinels and perovskites), and inorganic–organic composites (e.g., metal macrocycle derivatives). The design and optimization of air-electrode structure are also outlined. Furthermore, remarks on the challenges and perspectives of research directions are proposed for further development of metal–air batteries (219 references).