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Driven by potentially photo-electro-magnetic functionality, Bi-containing Aurivillius-type oxides of binary Bi4Ti3O12-BiFeO3 system with a general formula of Bin+1Fen−3Ti3O3n+3, typically in a naturally layered perovskite-related structure, have attracted increasing research interest, especially in the last twenty years. Benefiting from highly structural tolerance and simultaneous electric dipole and magnetic ordering at room temperature, these Aurivillius-phase oxides as potentially single-phase and room-temperature multiferroic materials can accommodate many different cations and exhibit a rich spectrum of properties. In this review, firstly, we discussed the characteristics of Aurivillius-phase layered structure and recent progress in the field of synthesis of such materials with various architectures. Secondly, we summarized recent strategies to improve ferroelectric and magnetic properties, consisting of chemical modification, interface engineering, oxyhalide derivatives and morphology controlling. Thirdly, we highlighted some research hotspots on magnetoelectric effect, catalytic activity, microwave absorption, and photovoltaic effect for promising applications. Finally, we provided an updated overview on the understanding and also highlighting of the existing issues that hinder further development of the multifunctional Bin+1Fen−3Ti3O3n+3 materials.

The plasmonic photovoltaic effect of mediation by surface plasmons in the harvesting of solar light energy in metallically surface-nanomodified photodiodes or solar cells is described in the microscopic manner. The experimentally observed increase in the efficiency of the photo-effect due to plasmons is explained by the competition between two opposing effects: that of the field concentration in plasmon oscillations and that of the admittance of indirect inter-band transitions in a semiconductor substrate induced by dipole coupling to plasmons at the nanoscale without translational invariance. The former effect favors larger metallic nanocomponents, whereas the latter effect prefers smaller nanocomponents. Both factors are quantitatively addressed within the quantum Fermi golden rule scheme, which allows for the size analysis of the plasmon effect and for its optimization. Experimental verification of the theoretical predictions is presented, including the demonstration of the proximity and size effect in double-layer photo-active substrate. The experiment reveals that the plasmon effect is still present if metallic nanoparticles are separated from substrate by the distance of order of 1 μm. [ABSTRACT FROM AUTHOR]

Thin films of Pb0.95La0.05Zr0.54Ti0.46O3were prepared using chemical solution method. The photovoltaic response of the films under dark and illuminated conditions was investigated using capacitor type devices with Pt as top and bottom electrodes. The results show that the open circuit voltage and the short circuit current of a capacitor type cell can be manipulated by controlling the post deposition annealing temperature of the films. Films annealed at 750°C were seen to exhibit the highest short circuit current of 15.83 nA. The influence of illumination on properties such as capacitance, ferroelectric polarization and leakage current was studied. The capacitance of the film was seen to decrease when illuminated with light (60mW/cm2), suggesting that illumination leads to generation of charge carriers. The films became leaky under illumination, resulting in an increase in leakage current by an order of magnitude compared to the dark conditions. The saturation polarization (Ps) was suppressed, whereas the remnant polarization (Pr) was not affected under illumination. Further, a shift in the hysteresis loop, along the voltage axis, was observed under illuminated conditions. This shift is attributed to the change of a space-charge field with illumination. [ABSTRACT FROM PUBLISHER]

We present strategies to improve low open-circuit voltage ( Voc) for ZnO-poly(3-hexylthiophene) (P3HT) photovoltaic devices, which are typically ≤0.4 V, but vary among different reports. One factor affecting Voc variability is the ZnO bandgap (E_g ), which depends on detailed processing conditions. By decreasing the pyrolysis temperature of sol–gel ZnO films, we increased the ZnO E_g by 0.14 eV and Voc of corresponding bilayer devices by 0.1 V. This is understood as increased donor–acceptor energy-level offset. Next, we demonstrate significant enhancement in V oc by depositing conformal amorphous TiO _x films at the surface of planar ZnO films and ZnO nanorod arrays using a spin-coating method. The TiO _x coatings monotonically increased Voc from 0.4 to 0.8 V for devices with increasing TiO_x thicknesses from 0 to ≥50 Å. Dark current–voltage measurement reveals that the TiO _x coating significantly decreases the reverse-bias current density, leading to an improvement in Voc, in excellent agreement with predictions from the modified ideal diode equation. This is consistent with passivation of ZnO surface defects by TiO _x. In short, by varying the solution processing conditions, we modify the bulk and interfacial properties of the metal oxide acceptor, thus leading to systematic improvement in open-circuit voltage. [ABSTRACT FROM PUBLISHER]

Driven by potentially photo-electro-magnetic functionality, Bi-containing Aurivillius-type oxides of binary Bi4Ti3O12-BiFeO3 system with a general formula of Bin+1Fen−3Ti3O3n+3, typically in a naturally layered perovskite-related structure, have attracted increasing research interest, especially in the last twenty years. Benefiting from highly structural tolerance and simultaneous electric dipole and magnetic ordering at room temperature, these Aurivillius-phase oxides as potentially single-phase and room-temperature multiferroic materials can accommodate many different cations and exhibit a rich spectrum of properties. In this review, firstly, we discussed the characteristics of Aurivillius-phase layered structure and recent progress in the field of synthesis of such materials with various architectures. Secondly, we summarized recent strategies to improve ferroelectric and magnetic properties, consisting of chemical modification, interface engineering, oxyhalide derivatives and morphology controlling. Thirdly, we highlighted some research hotspots on magnetoelectric effect, catalytic activity, microwave absorption, and photovoltaic effect for promising applications. Finally, we provided an updated overview on the understanding and also highlighting of the existing issues that hinder further development of the multifunctional Bin+1Fen−3Ti3O3n+3 materials. [ABSTRACT FROM AUTHOR]