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Hybrid photocatalysts consisting of single crystalline BiFeO3 nanowires and laser ablated Au nanoparticles were synthesized by a functionalization-step-free solution process. The 1.0 wt% Au nanoparticle decorated BiFeO3 nanowires exhibit ~30 times higher photocatalytic activity for water oxidation than that exhibited by the parent wires during the first 4 h.

We describe a fast and effective procedure for the preparation of high efficiency hybrid photoanodes for dyesensitized solar cells (DSCs), based on nanocrystalline TiO 2 with limited addition of multiwall carbon nanotubes (CNTs). The mixing process between CNTs and TiO 2 nanoparticles is almost instantaneous, which makes it feasible for large-scale fabrication. Enhanced electron lifetime and reduced charge recombination lead to highly increased short circuit current density and overall photoconversion efficiency (from 13.6 mA cm −2 to 16.0 mA cm −2 and from 7.0% to 9.0%, respectively, considering the bare TiO 2 and the optimum CNTs concentration, which is 0.010 wt %), while the small reduction in open circuit photovoltage does not significantly affect cell performances. This result is remarkable since a standard dye molecule (N719) was used and no chemical treatments of the photoanodes prior to cell fabrication were applied (i.e., soaking in TiCl 4 to boost open circuit photovoltage).

We report the structural and physical properties of epitaxial Bi 2 FeCrO 6 thin films on epitaxial SrRuO 3 grown on (100)-oriented SrTiO 3 substrates by pulsed laser ablation.The 300 nm thick films exhibit both ferroelectricity and magnetism at room temperature with a maximum dielectric polarization of 2.8 µC/cm 2 at E max = 82 kV/cm and a saturated magnetization of 20 emu/cc (corresponding to ~ 0.26 µ B per rhombohedral unit cell), with coercive fields below 100 Oe. Our results confirm the predictions made using ab-initio calculations about the existence of multiferroic properties in Bi 2 FeCrO 6 .

In recent years, hybrid organic-inorganic halide perovskites have been widely studied for the low-cost fabrication of a wide range of optoelectronic devices, including impressive perovskite-based solar cells. Amongst the key factors influencing the performance of these devices, recent efforts have focused on tailoring the granularity and microstructure of the perovskite films. Albeit, a cost-effective technique allowing to carefully control their microstructure in ambient environmental conditions has not been realized. We report on a solvent-antisolvent ambient processed CH3NH3PbI3−xClx based thin films using a simple and robust solvent engineering technique to achieve large grains (>5 µm) having excellent crystalline quality and surface coverage with very low pinhole density. Using optimized treatment (75% chlorobenzene and 25% ethanol), we achieve highly-compact perovskite films with 99.97% surface coverage to produce solar cells with power conversion efficiencies (PCEs) up-to 14.0%. In these planar solar cells, we find that the density and size of the pinholes are the dominant factors that affect their overall performances. This work provides a promising solvent treatment technique in ambient conditions and paves the way for further optimization of large area thin films and high performance perovskite solar cells.

Hybrid organic–inorganic perovskites have shown exceptional semiconducting properties and microstructural versatility for inexpensive, solution‐processable photovoltaic and optoelectronic devices. In this work, an all‐solution‐based technique in ambient environment for highly sensitive and high‐speed flexible photodetectors using high crystal quality perovskite nanowires grown on Kapton substrate is presented. At 10 V, the optimized photodetector exhibits a responsivity as high as 0.62 A W−1, a maximum specific detectivity of 7.3 × 1012 cm Hz1/2 W−1, and a rise time of 227.2 µs. It also shows remarkable photocurrent stability even beyond 5000 bending cycles. Moreover, a deposition of poly(methyl methacrylate) (PMMA) as a protective layer on the perovskite yields significantly better stability under ambient air operation: the PMMA‐protected devices are stable for over 30 days. This work demonstrates a cost‐effective fabrication technique for high‐performance flexible photodetectors and opens opportunities for research advancements in broadband and large‐scale flexible perovskite‐based optoelectronic devices.

We report a large photovoltaic (PV) effect in multiferroic Bi2FeCrO6 (BFCO) films under monochromatic illumination at 635 nm with an intensity of 1.5 mW cm−2. These multiferroic films exhibit a large photocurrent at zero bias voltage and an open-circuit voltage of about 0.6 V. A high PV power conversion efficiency of about 6% for red light is achieved and attributed to a high degree of B-site cationic ordering between Fe and Cr sublattices, the tuning of which is likely to play a key role in further improvements of the PV properties in BFCO.