Renewable Energy, Sustainability and the Environment, Renewable Energy, Sustainability and the Environment
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Scopus Publications
Scopus Publications
Ferroelectric Metal–Organic Frameworks as Wide Band Gap Materials Monirul Shaikh, Sathiyamoorthy Buvaneswaran, Asif Latief Bhat, Trilochan Sahoo, Saurabh Ghosh Journal of Physical Chemistry C, 2026 Wide band gap materials are particularly relevant at high temperatures. The band gap shrinkage at higher temperatures prevents device applications with narrow band gap semiconductors. Considering α-phase strontium cyanurate as a prototype structure, we identify a group of metal–organic frameworks (MOFs) that exhibit ultrawide band gaps ranging from 5.5 to 5.7 eV. Recently, a strontium cyanurate compound was found to undergo a phase transition from a high-symmetry β-phase to a low-symmetry ferroelectric α-phase when the temperature was reduced. In the present study, utilizing group theory techniques, we unravel that a zone-center Γ 2 – phonon mode modifies our structures from a high-symmetry β-phase to a low-symmetry α-phase for A 3 (O 3 C 3 N 3 ) 2 MOFs with A = Mg, Ca, Sr, and Ba. We implement first-principles calculations to investigate structural, ferroelectric, and optical properties of these compounds in the α-phase. The switching barriers between bistable polar states are also estimated. Furthermore, to realize their feasibility, we examine the dynamical and thermal stabilities for all of these MOFs.
Emergence of insulating ferro- and ferrimagnetism with enhanced optical properties in double-double perovskite oxides Monirul Shaikh, Fengyi Zhou, Sathiyamoorthy Buvaneswaran, Rajan Gowsalya, Trilochan Sahoo, Duo Wang, Saurabh Ghosh Physical Review B, 2025 The emergence of ferro- and ferrimagnetic behavior in insulating materials is uncommon, largely due to Hund's rules. Utilizing symmetry analysis, first-principles methods, and classical Monte Carlo simulations, we report technologically important insulating ferro- and ferrimagnetic double-double perovskite oxides. Our study predicts ${\text{La}A}^{\ensuremath{'}}{\mathrm{MnNiO}}_{6}$ (${A}^{\ensuremath{'}}=\mathrm{V}$, Cr, Mn, Co, and Ni) as promising candidates for spintronic and optical applications exhibiting band gaps between 1.3 and 1.9 eV. We explain the mechanisms driving band-gap openings and magnetic exchange interactions in these ferro- and ferrimagnetic compounds. Monte Carlo simulations together with state-of-the-art orbital-decomposed exchange parameter analysis reveal intriguing variations in magnetic transition temperatures (up to 242 K) and the corresponding exchange mechanisms in all ${\text{La}A}^{\ensuremath{'}}{\mathrm{MnNiO}}_{6}$ compounds. In addition, we assess the thermodynamic and dynamic stability of these compounds to comment on the feasibility of these systems.
Ferroelectric ferrimagnetic double perovskite oxides design for optoelectronics Sathiyamoorthy Buvaneswaran, Monirul Shaikh, Trilochan Sahoo, Saurabh Ghosh Physical Review Materials, 2025 Magnetoelectric multiferroic semiconductors offer great promise for applications in magnetic storage, optoelectronics, and advanced spintronics. These materials require strong magnetization, polarization, a moderate energy gap ($1.5\phantom{\rule{0.16em}{0ex}}\text{eV}<{E}_{g}<3\phantom{\rule{0.16em}{0ex}}\text{eV}$), and high transition temperatures for both ferroelectric and ferromagnetic properties. This paper investigates six double perovskite oxides (DPOs), ${AA}^{\ensuremath{'}}{\mathrm{FeOsO}}_{6}$ ($A$ = Na, K, Rb; ${A}^{\ensuremath{'}}$= La, Y), as potential candidates. We used density functional theory to find that DPOs exhibit a polar $\mathrm{P}{2}_{1}$ phase with an ${a}^{\ensuremath{-}}{a}^{\ensuremath{-}}{c}^{+}$ tilt pattern. The polarization results from the noncancellation of layered polarization between $A\mathrm{O}$ and ${A}^{\ensuremath{'}}\mathrm{O}$ layers, which can be switched by altering their relative displacement. The strong antiferromagnetic coupling between ${\mathrm{Fe}}^{3+}$ ($S$ = 5/2) and ${\mathrm{Os}}^{5+}$ ($S$ = 3/2) leads to a stable ferrimagnetic ground state. These materials demonstrate semiconducting properties with a band gap ${E}_{g}\phantom{\rule{0.28em}{0ex}}<$ 3 eV and strong absorption in both the visible and ultraviolet regions. Ab initio molecular dynamics simulations show that the ferroelectric polarization switching temperatures exceed 300 K, making these materials suitable for room-temperature applications.
Dual Modifications of TiO2/1D g-C3N4 Nanocomposites and Metal-Organic Framework-Derived Porous CuO/Carbon for High-Performance Perovskite Solar Cells Nandhakumar Eswaramoorthy, Satheesh Kuppusamy, Keerthana Manoharan, Sathiyamoorthy Buvaneswaran, Arunkumar Prabhakaran Shyma, Trilochan Sahoo, Krishna Chandar Nagamuthu Raja, Selvakumar Pitchaiya, Prabhakaran Deivasigamani, Kamatchi Rajaram ACS Applied Nano Materials, 2024 This study uses a sonication method to fabricate a light-harvesting structure on an anatase phase TiO2/1D g-C3N4 nanocomposite electron transport material. In addition, two different metal–organic framework (MOF)-derived porous CuO (CuO-I and CuO-II) are used to modify the carbon electrode. The open atmospheric fabricated TiO2/1D g-C3N4 layer exhibits a maximum power conversion efficiency (PCE) of 6.95% than anatase phase TiO2 (5.40%). Furthermore, the PCE of organometallic perovskite solar cells exhibits 10.03 and 8.43% for CuO-I and CuO-II-modified carbon electrodes. Results reveal that CuO/carbon composite exhibits superior characteristics to commercial carbon electrodes due to increased specific surface area, porosity, and device stability. This dual modification device shows excellent device stability under ambient, thermal, and photostability analysis under AM 1.5 solar irradiation.
Design of Ferroelectric Double Perovskite Oxides as Photovoltaic Materials Sathiyamoorthy Buvaneswaran, Monirul Shaikh, Rajan Gowsalya, Trilochan Sahoo, Saurabh Ghosh Journal of Physical Chemistry C, 2023 In ferroelectric-based photovoltaic materials, spontaneous polarization is expected to couple with the electronic and optical properties of the materials, and such materials have drawn attention as photovoltaic solar cells. Here, we utilize hybrid improper ferroelectricity to induce ferroelectric polarization in selected A-site layered and B-site rock-salt AA′BB′O 6 double perovskites and propose an alternate route to design ferroelectric photovoltaic semiconductors. First-principles density functional theory calculations and ab initio molecular dynamics simulations are performed to investigate the optical, electronic, and ferroelectric properties. We consider RbLaMnWO 6 and RbYMnWO 6 as model systems to pursue this study. We identify that these materials are semiconductors with a minimalist forbidden energy gap ( E g ) of 2.31 and 2.14 eV, respectively. This facilitates their absorption within the visible light region, thus enabling them to be exploited for optical device applications. The optical transition occurring in RbLaMnWO 6 reveals the relationship between the absorption spectrum and its electronic structure. We notice a low ferroelectric switching barrier in the case of RbLaMnWO 6, whereas a low band gap is espied in RbYMnWO 6 . To utilize the large visible spectra, we lower the band gap of RbYMnWO 6 from 2.14 to 1.67 eV by strain engineering. Similar structural, electronic, and optical properties are obtained for A-site substitution (A = K, Na). Further, molecular dynamics simulations show a polarization switching occurring at a temperature ( T ) of ∼400 K in RbLaMnWO 6 . This, in turn, enhances the dielectric response of RbLaMnWO 6 during switching and can be a potential candidate for designing optoelectronic materials where the structure–property relation can be controlled by electric field and/or temperature.
Time dependent defect in periodic dielectric waveguide for path delay multiplexing in distributed fiber sensor Bragg Gratings Photosensitivity and Poling in Glass Waveguides Bgpp 2014, 2014
Time dependent defect in periodic dielectric waveguide for path delay multiplexing in distributed fiber sensor Nonlinear Photonics Np 2014, 2014
