https://libjncir.jncasr.ac.in/xmlui/handle/10572/1494 Sat, 04 Apr 2026 05:30:37 GMT 2026-04-04T05:30:37Z https://libjncir.jncasr.ac.in/xmlui/handle/10572/2557 Functional Corannulene: Diverse Structures, Enhanced Charge Transport, and Tunable Optoelectronic Properties Sanyal, Somananda; Manna, Arun K.; Pati, Swapan Kumar Chemical functionalization of various hydrocarbons, such as coronene, corannulene, and so forth, shows good promise in electronics applications because of their tunable optoelectronic properties. By using quantum chemical calculations, we have investigated the changes in the corannulene buckybowl structure, which greatly affect its electronic and optical properties when functionalized with different electron-withdrawing imide groups. We find that the chemical nature and position of functional groups strongly regulate the stacking geometry, -stacking interactions, and electronic structure. Herein, a range of optoelectronic properties and structure-property relationships of various imide-functionalized corannulenes are explored and rationalized in detail. In terms of carrier mobility, we find that the functionalization strongly affects the reorganization energy of corannulene, while the enhanced stacking improves hopping integrals, favoring the carrier mobility of crystals of pentafluorophenylcorannulene-5-monoimide. The study shows a host of emerging optoelectronic properties and enhancements in the charge-transport characteristics of functionalized corannulene, which may find possible semiconductor and electronics applications. Restricted Access Wed, 01 Jan 2014 00:00:00 GMT https://libjncir.jncasr.ac.in/xmlui/handle/10572/2557 2014-01-01T00:00:00Z https://libjncir.jncasr.ac.in/xmlui/handle/10572/2558 Improved catalytic activity of rhodium monolayer modified nickel (110) surface for the methane dehydrogenation reaction: a first-principles study Bothra, Pallavi; Pati, Swapan Kumar The catalytic activity of pure Ni (110) and single Rh layer deposited Ni (110) surface for the complete dehydrogenation of methane is theoretically investigated by means of gradient-corrected periodic density functional theory. A detailed kinetic study, based on the analysis of the optimal reaction pathway for the transformation of CH4 to C and H through four elementary steps (CH4 -> CH3 + H; CH3 -> CH2 + H; CH2 -> CH + H; CH -> C + H) is presented for pure Ni (110) and Rh/Ni (110) surfaces and compared with pure Rh (110) surface. Through systematic examination of adsorbed geometries and transition states, we show that single layer deposition of Rh on Ni (110) surface has a striking influence on lowering the activation energy barrier of the dehydrogenation reaction. Moreover, it is found that a pure Ni (110) surface has a tendency for carbon deposition on the catalytic surface during the methane dissociation reaction which decreases the stability of the catalyst. However, the deposition of carbon is largely suppressed by the addition of a Rh overlayer on the pure Ni (110) surface. The physical origin of stronger chemisorption of carbon on Ni (110) relative to Rh/Ni (110) has been elucidated by getting insight into the electronic structures and d-band model of the catalytic surfaces. Considering the balance in both the catalytic activity as well as the catalyst stability, we propose that the Rh/Ni (110) surface possesses much improved catalytic property compared to pure Ni (110) and pure Rh (110) surfaces. Restricted Access Wed, 01 Jan 2014 00:00:00 GMT https://libjncir.jncasr.ac.in/xmlui/handle/10572/2558 2014-01-01T00:00:00Z https://libjncir.jncasr.ac.in/xmlui/handle/10572/2554 Effects of edge passivations on the electronic and magnetic properties of zigzag boron-nitride nanoribbons with even and odd-line stone-wales (5-7 pair) defects Yamijala, Sharma S. R. K. C.; Pati, Swapan Kumar First-principles spin-polarized calculations have been performed on passivated boron-nitride nanoribbons (BNNRs) with pentagon-heptagon line-defects (PHLDs), also called as Stone-Wales line-defects. Two kinds of PHLDs, namely, even-line and odd-line PHLDs, have been added either at one edge or at both edges of BNNRs. Single-edge (with all its different possibilities, for example, for a BNNR with 2-line PHLD at single-edge there are eight possibilities) as well as both-edge passivations have been considered for all the ribbons in this study by passivating each edge atom with hydrogen atom. Density of states (DOS) and projected-DOS analysis have been accomplished to understand the underlying reason for various properties. We find that passivation lead to different effects on the electronic and magnetic properties of a system, and the effects are mainly based on the line-defect introduced and/or on the atoms which are present at the passivated edge. In general, we find that, passivation can play a key role in tuning the properties of a system only when it has a zigzag edge. Restricted Access Wed, 01 Jan 2014 00:00:00 GMT https://libjncir.jncasr.ac.in/xmlui/handle/10572/2554 2014-01-01T00:00:00Z https://libjncir.jncasr.ac.in/xmlui/handle/10572/2555 Electronic properties of zigzag, armchair and their hybrid quantum dots of graphene and boron-nitride with and without substitution: A DFT study Yamijala, Sharma S. R. K. C.; Bandyopadhyay, Arkamita; Pati, Swapan Kumar Spin-polarized density functional theory calculations have been performed on armchair graphene quantum dots and boron-nitride quantum dots (AG/BNQDs) and the effect of carbon/boron-nitride sub-stitution on the electronic properties of these AG/BNQDs has been investigated. As a first step to consider more realistic quantum dots, quantum dots which are a combination of zigzag QDs and armchair QDs have been considered. Effect of substitution on these hybrid quantum dots has been explored for both GQDs and BNQDs and such results have been compared and contrasted with the results of substituted AG/BNQDs and their zigzag analogs. Our work suggests that the edge substitution can play an important tool while tuning the electronic properties of quantum dots. (C) 2014 Elsevier B. V. All rights reserved. Restricted Access Wed, 01 Jan 2014 00:00:00 GMT https://libjncir.jncasr.ac.in/xmlui/handle/10572/2555 2014-01-01T00:00:00Z