Polymer-Assisted Single-Step Slot-Die Coating of Flexible Perovskite Solar Cells at Mild Temperature from Dimethyl Sulfoxide.

The industrialization of perovskite solar cells relies on solving intrinsic-to-material issues. To reach record efficiencies perovskite deposition needs to be finely adjusted by multi-step processes, in a humidity free glove-box environment and by means of hardly scalable techniques often associated with toxic solvents and anti-solvent dripping/bath. Herein, the use of polymeric material is proposed to deposit perovskite layers with easy processability. To the scope, a starch-polymer/perovskite composite is developed to suit slot-die coating technique requirement, allowing the deposition of hybrid halide perovskite material in a single straightforward step without the use of toxic solvents, and in uncontrolled humid environment (RH up to 70 %). The starch-polymer increases the viscosity of the perovskite precursor solutions and delays the perovskite crystallization that results in the formation of perovskite films at mild temperature (60 °C) with good morphology. These innovative inks enables the fabrication of flexible solar cells with p-i-n configuration featured by a power conversion efficiency higher than 3 %. . Overall, this approach can be exploited in the future to massively reduce perovskite manufacturing costs related to keeping the entire fabrication line at high-temperature and under nitrogen or dry conditions.

Microscope-Assisted Episcleral Surgery with Encircling Buckles and Chandelier Endoillumination for Primary Rhegmatogenous Retinal Detachment in Phakic and Pseudophakic Patients: A 12-Month Comparative Study.

INTRODUCTION: The aim of the study was to compare postoperative outcomes after microscope-assisted encircling buckle and chandelier endoillumination for primary rhegmatogenous retinal detachment (RRD) in phakic and pseudophakic (PFK) patients. METHODS: 121 eyes of 117 patients were divided into 2 groups depending on the lens status (group 1, PFK, 53 eyes; group 2, phakic, 68 eyes). The main outcomes include retinal reattachment rate (RRR) and best-corrected visual acuity (BCVA) at 1 week, 1, 3, 6, and 12 months. RESULTS: The overall primary RRR was 91.7% (111/121). In group 1, the primary RRR was 90.6% (48/53), whereas in group 2 it was 92.6% (63/68). The mean preoperative BCVA improved in both groups at 12 months. Undetected retinal breaks were found in 9.9% of cases. When an encircling 5-mm oval sponge was used, no additional exoplants were required and transcleral drainage was performed in 89.7% of the eyes. In group 1, among the 5 PFK eyes with persistent RRD, 4 eyes had a sulcus intraocular lens. CONCLUSIONS: Microscope-assisted episcleral surgery with chandelier endoillumination is an effective technique for primary RRD in both phakic and PFK eyes with uncomplicated cataract surgery. Chandelier endoilluminators help to visualize undetected retinal breaks, especially in PFK eyes. In case of a circumferential 5-mm oval sponge, additional exoplants are not required and transcleral drainage is strongly recommended to flatten the retina by closing the causative breaks.

Sculpturing patterns of plasmonic silver nanoprisms by means of photocatalytic lithography.

The controlled shaping of nanoparticles' morphology is one of the pillars of nanotechnology. Here, we demonstrate that photocatalytic lithography, a technique already proved to be useful in materials science, can act as a dry etching technique for noble metal nanoparticles. Triangular silver nanoprisms are self-assembled on titanium dioxide films and photocatalytically shaped into discoidal particles upon irradiation with near-UV light. The obtained patterned surfaces show a dramatically different surface-enhanced Raman scattering response, suggesting the utility of our approach for the development of sensors. The photocatalytic nature of the particle shaping is demonstrated and a plausible mechanism drawn by performing photocatalysis in different configurations (direct and remote) and by irradiating in different solvents.

Neat C70-based bulk-heterojunction polymer solar cells with excellent acceptor dispersion.

The replacement of common fullerene derivatives with neat-C70 could be an effective approach to restrain the costs of organic photovoltaics and increase their sustainability. In this study, bulk-heterojunction solar cells made of neat-C70 and low energy-gap conjugated polymers, PTB7 and PCDTBT, are thoroughly investigated and compared. Upon replacing PC70BM with C70, the mobility of positive carriers in the donor phase is roughly reduced by 1 order of magnitude, while that of electrons is only slightly modified. It is shown that the main loss mechanism of the investigated neat-C70 solar cells is a low mobility-lifetime product. Nevertheless, PCDTBT:C70 devices undergo a limited loss of 7.5%, compared to the reference PCDTBT:PC70BM cells, reaching a record efficiency (4.44%) for polymer solar cells with unfunctionalized fullerenes. The moderate efficiency loss of PCDTBT:C70 devices, due to an unexpected excellent miscibility of PCDTBT:C70 blends, demonstrates that efficient solar cells made of neat-fullerene are possible. The efficient dispersion of C70 in the PCDTBT matrix is attributed to an interaction between fullerene and the carbazole unit of the polymer.

Photoanodes based on nanostructured WO3 for water splitting.

Anodically grown WO(3) photoelectrodes prepared in an N-methylformamide (NMF) electrolyte have been investigated with the aim of exploring the effects induced by anodization time and water concentration in the electrochemical bath on the properties of the resulting photoanodes. An n-type WO(3) semiconductor is one of the most promising photoanodes for hydrogen production from water splitting and the electrochemical anodization of tungsten allows very good photoelectrodes, which are characterized by a low charge-transfer resistance and an increased spectral response in the visible region, to be obtained. These photoanodes were investigated by a combination of steady state and transient photoelectrochemical techniques and a correlation between photocurrent produced, morphology, and charge transport has been evaluated.