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Low dimensional (2D, 1D) lead halide perovskites are currently attracting huge research interest due to their enabling properties. Demonstrating synthetic control on the dimensionality/structure of...

Lanthanide doped TiO2 photoanodes were optimized and employed to enhance the DSSC performance in indoor-light illumination. We report efficiencies ≈ 9% for indoor conditions that are twice that measured under the solar simulator.

The eco-friendly Na0.5Bi0.5TiO3 (NBT) and its derivatives have been synthesized by conventional solid state route. According to Judd-Ofelt theory, the higher symmetry phase suppresses the e...

Herein, we describe a facile method to introduce SPR-effect in MAPbBr3 -QDs/TiO2 interface. SPR enabled efficient electron-transfer is confirmed by photoluminescence (PL) quenching and short PL lifetimes (3.4 ns) of MAPbBr3 from TiO2/Au-NPs/MAPbBr3-QD thin film.

The single phase nano-crystalline lead-free Na0.5Bi0.5TiO3 (NBT) synthesized using hydrothermal technique produces homogeneous crystalline powders. The structural phase purity of these ceramic powders was confirmed by using room temperature X-ray diffraction and it revealed that the structure stabilizes in rhombohedral (R3c) phase. The microstructure from scanning electron microscopy clearly showed the cubic-type feature in orders of 100-200 nm with sharp face edges. The Curie temperature (TC), dielectric constant (er) and other electrical properties are strongly dependent on the particle sizes. The dielectric constant (er = 3100 at 100 kHz) is high in comparison to reported NBT synthesized using solid state route (er = 2700 at 100 kHz). Additionally, diffusive phase transition was clearly observed in nano NBT powders which supports its tendency towards more relaxor behavior and will be a pertinent candidate to improve the energy storage capacity.

Recent studies on (0.96)Na0.5Bi0.5TiO3–(0.04)BaTiO3 (NBT-4BT)solid solution reveal the existence of the structural distortion of lower symmetric Cc phase rather than the R3c phase through high resolution X-ray diffraction and neutron diffraction. The Nd-modified NBT-4BT can be thought of a possible candidate for switchable optical properties and has been chosen for present studies. The structural distortion in this solid solution is found to be mixture of two structural phases. The coexistence of Cc along with minor phase reflections of P4mm was confirmed through structural refinement The systematic study of structural, electrical and optical properties on this solid solution has been performed.

Nanocrystalline Pr3+ substituted NBT was synthesized using hydrothermal technique. Pr3+ modifies the ferroelectric NBT optically active and enhances the electrical properties with small structural changes. Aiming to the development of the bottom up optoelectronic devices this optimized nanoscale Na0.5Bi0.5-xPrxTiO3(x = 0.005) compound is synthesized hydrothermally. X-ray diffraction pattern shows that the system is stabilized in the Rhombohedral (space groupR3c) phase indicating the local strain inhomogeneity. PE loop shows that there is a decrement in the Ec value compared with compounds synthesized using conventional methods. The strong red emission assigned to prominent transition of the Pr3+ ions at 610nm was observed along with weak blue-green emission, indicating the potential use of the system. Energy transfer from host system to Pr3+ ions is responsible for red emission while blue green emission is due to quenching of 3P0 induced by intervalence charge transfer state.

The localized surface plasmon dynamics of laser ablated gold and gold-silver alloy nanoparticles (NPs) near interband and intraband excitation wavelengths were investigated using femtosecond (fs) transient absorption spectroscopy. Interband excitation with 70 fs laser pulses at a wavelength of 400 nm demonstrated plasmon photo-bleach and a transient absorption in the wings of the bleach spectrum. With intraband excitation, Ag50Au50 alloy NPs depicted a fast electron thermalization time of ~180 fs. A slower decay of positive absorption from alloy NPs was observed when compared to pure Au NPs. These NPs demonstrated a rapid initial electron thermalization and exhibited similar electron-phonon relaxation times. The third-order nonlinear optical (NLO) properties were measured using the Z-scan technique with 1 kHz repetition rate fs pulses at 800 nm. It is observed that the alloy NPs possessed large value of the NLO susceptibility χ(3) (~10−13 esu) compared to pure gold NPs at 800 nm finding applications in different areas of photonics.