Moumita Kar

This work applies theoretical and computational methods to investigate the relationship between phosphorescence lifetime and the electronic character of the lowest triplet state of aromatic carbonyls. A formal analysis of the spin-perturbed wave functions shows that phosphorescence is due to a direct spin–orbit coupling mechanism modulated by perma...

This work applies theoretical and computational methods to investigate the relationship between phosphorescence lifetime and the electronic character of the lowest triplet state of aromatic carbonyls. A formal analysis of the spin-perturbed wave functions shows that phosphorescence is due to a direct spin-orbit coupling mechanism modulated by perma...

This work uses theoretical and computational methods to investigate the relationship between phosphorescence lifetime and the electronic character of the lowest triplet state of aromatic carbonyls. It shows that phosphorescence is due to a direct spin-orbit coupling (SOC) mechanism modulated by permanent dipoles when the T1 minimum is 3np*. If the...

An organic-inorganic nanohybrid system (AMC-CdS QD) comprised of a fluorescent carbazole analog, AMC (3-amino-N-methyl carbazole), and CdS QDs has been synthesized, which shows promise as a sustainable energy harvesting material. FT-IR and ¹H NMR spectroscopy have ascertained the covalent grafting of the carbazole moieties onto the mercaptopropioni...

Using density functional theory we have predicted new chromium carbide (CrC) monolayers with unique intrinsic ferromagnetism, high Curie temperature and high spin polarization. The 2D h-CrC emerges as graphene like planer structure, while t-CrC comes out as a buckled structure. The ab-initio molecular dynamics simulation and phonon dispersion spect...

Recently, two-dimensional organic–inorganic hybrid perovskites have attracted great attention for their outstanding performances in solar energy conversion devices. By using first principles calculations, we explored the structural, electronic and optical properties of recently synthesized (PEA)2PbI4 and (PEA)2SnI4 organic–inorganic hybrid perovski...

Carbon nanotubes (CNTs) are appealing candidates for solar and optoelectronic applications. Traditionally used as electron sinks, CNTs can also perform as electron donors, as exemplified by coupling with perylenediimide (PDI). To achieve high efficiencies, electron transfer (ET) should be fast, while subsequent charge recombination should be slow....

Half metallic materials with intrinsic ferromagnetism are identified as the pillar of next generation spintronic devices. In search of new low-dimensional materials with these excellent properties, herein we systematically study the electronic and magnetic properties of edge dependent (armchair (ac) and zigzag (zz)) vanadium nitride nanoribbons (VN...

In this article, we propose a new two-dimensional CP3 material with distinguished properties from comprehensive first-principles calculations. It has excellent thermal, mechanical, and dynamical stabilities and promise for experimental fabrication. The low cleavage energy (0.57J/m2) implies the plausibility of CP3 single-layer exfoliation from bulk...

By using the density functional method, we explore the potentiality of recently synthesized CdX (X=Se, Te)QD/P3HT composites in solar energy conversion devices. Our study reveals that inorganic/organic hybrid CdXQD/P3HT nanocomposites with larger size of CdX QDs exhibit type-II band alignment, suggesting efficient charge separation upon photoexcita...

Designing the efficient inorganic/organic hybrid light harvesting systems through understanding of charge generation, separation and recombination dynamics is an important pathway for improvement of power conversion efficiency (PCE) of photovoltaic cell. Using density functional method, we explored the photovoltaic performance of recently synthesiz...

Nonradiative electron-hole (e-h) recombination is the primary source of energy loss in photovoltaic cell and inevitably it competes with the charge transfer process, leading to a poor device performance. Therefore, much attention is needed for delaying such process; increase in excitonic lifetime may be a remedy for that. Using real-time, density f...

By using the state-of-the-art theoretical method, we herein explore the potentiality of covalently linked periodically-ordered 1D chain, 2D hexagonal and square ordered superstructures of CdTe QDs in photovoltaics. One of the major factors that controls the photovoltaic efficiency is the electron-hole recombination which in turn depends on the spat...

Using the density functional method, we demonstrate that edge modified phosphorene antidot nanoflakes (PANFs) and their van der Waals heterojunctions are the new entity for novel light-electricity conversion. We have herein studied H, OH and CN edge passivated PANFs (PANF_H, PANF_OH and PANF_CN) of different lengths and pore sizes. Our study reveal...

The porosity of newly synthesized phosphorene antidot lattice (PAL) has promise to enca-pasulate the porphyrin molecule and thus shows a versatile route to fabricate porphyrin-PAL nanocomposites. We herein explore the photovoltaic performance of tetraphenylporphyrin (TPP)/PAL composite system. Interestingly, TPP/PAL composites show type-II staggere...

Using first-principles calculations, we have studied the energetic feasibility and magnetic properties of transition metal (TM) doped PtSe2 monolayers. Our study shows that TM doped PtSe2 layers with 6.25% doping exhibit versatile spintronic behaviour depending on the nature of the dopant TM atoms. Groups IVB and VIII10 TM doped PtSe2 layers are no...

We have investigated the structure, stability and the electronic properties of bare and edge hydrogenated tin sulphide nanoribbons (SnSNRs) using first-principles density functional theory calculation. In contrast to the 2D sheet of SnS, which is an indirect band gap semiconductor, bare 1D SnSNRs are either metallic (in case of zigzag (zz) edge ter...

Using the self-consistent charge density-functional based tight-binding (SCC-DFTB) method, coupled with time-dependent density functional theory (TDDFT) calculations, for the first time we explore the possibility of use of phosphorene quantum dots in solar energy harvesting devices. The phosphorene quantum dots-fullerene (PQDs-PCBA) nanocomposites...