The physical properties of two-dimensional (2D) lead halide based hybrid perovskites are quite exciting and challenging. Further, the role of organic cations in 2D perovskites is still in a debate. We investigated layered (CH 3 (CH 2 ) 3 NH 3 ) 2 (CH 3 NH 3 )Pb 2 I 7 2D Ruddlesden−Popper (2DRP) phase (M1) and 2D derivative of CH 3 NH 3 PbI 3 (M2) using density functional theory. The spin orbit coupling mediates the significantly large Rashba splitting energy of 328.5 meV for M2, which is higher than earlier 2D hybrid perovskites. At the picosecond time scale, the dynamical Rashba effect was observed due to organic and inorganic cation dynamics. Two step absorption suggests an indirect optical gap of 2.38 and 2.15 eV for M1 and M2, respectively and solar performance depicts excellent power conversion efficiency of 14.92% and 19.75% for M1 and M2, respectively. For the first time, we explored the thermoelectric properties of 2D hybrid perovskites and perceived high power factor for p-type doping in M2. Our findings suggest that these novel 2D perovskites have the potential to be used in solar and heat energy harvesting.

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The influence of the length of the alkyl chain and water molecules on the hydrogen-bond interaction of the chloride anion and imidazolium-based cation of the ionic liquid (IL) C_nmim Cl...

The pivotal impact of organic cation rotation may render structural complexity in two-dimensional (2D) halide-based hybrid perovskites. The crucial role of the orientation of organic cation (MA = CH3NH3+) in...

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Hydrogen energy has received significant attention in the renewable energy sector due to its high energy density and environmentally friendly nature. For the efficient hydrogen generation from water, the hydrogen evolution reaction (HER) has to be optimized, which requires a highly efficient electrocatalyst. In this work, a hybrid structure of the ionic liquid (IL) 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (C2mim TfO) and (TiO2) n nanoclusters with n = 2–12 has been investigated in the pursuit of new catalyst materials for effective HER. We have employed state-of-the-art density functional theory (DFT) computations to depict the HER catalytic performance of IL/(TiO2) n hybrid systems through Gibbs free energy (ΔG) and an exchange-current-based “volcano” plot. We have explored the effect of the TiO2 nanoclusters on the structural and electronic characteristics of the IL, calculating the adsorption energy, the energies of the highest occupied (HOMO) and lowest unoccupied molecular orbitals (LUMO), the HOMO–LUMO band gap E g, and the work function ϕ. The variation in size of the TiO2 nanocluster in the IL/(TiO2) n hybrid system was found to have a significant influence on the electronic properties. The obtained results suggest that the ΔG of the hydrogen adsorption is remarkably close to the ideal value (0 eV) for the IL/(TiO2)5 system, which also reflects from the volcano plot, suggesting that this complex is the best HER catalyst among the studied systems; it might be even better than the traditional Pt-based catalyst. Thus, the present work suggests ways for the experimental realization of low-cost and multifunctional IL-based hybrid catalysts for clean and renewable hydrogen energy production.

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Achieving benchmark enhancement in the thermoelectric figure of merit through the fluorination of SiGe monolayers at room temperature.