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Implementation of resonant colloidal nanoparticles for improving performance of organometal halide perovskites solar cells is highly prospective approach, because it is compatible with the solution processing techniques used for any organic materials. Previously, resonant metallic nanoparticles have been incorporated into perovskite solar cells for better light absorption and charge separation. However, high inherent optical losses and high reactivity of noble metals with halides in perovskites are main limiting factors for this approach. In turn, low-loss and chemically inert resonant silicon nanoparticles allow for light trapping and enhancement at nanoscale, being suitable for thin film photovoltaics. Here photocurrent and fill-factor enhancements in meso-superstructured organometal halide perovskite solar cells, incorporating resonant silicon nanoparticles between mesoporous TiO2 transport and active layers, are demonstrated. This results in a boost of the device efficiency up to 18.8\% and fill factor up to 79\%, being a record among the previously reported values on nanoparticles incorporation into CH3NH3PbI3 (MAPbI3) perovskites based solar cells. Theoretical modeling and optical characterization reveal the significant role of Si nanoparticles for increased light absorption in the active layer rather than for better charge separation. The proposed strategy is universal and can be applied in perovskite solar cells with various compositions, as well as in other optoelectronic devices.

We report on the heterogeneous nucleation of catalyst-free InAs nanowires on Si (111) substrates by chemical beam epitaxy. We show that nanowire nucleation is enhanced by sputtering the silicon substrate with energetic particles. We argue that particle bombardment introduces lattice defects on the silicon surface that serve as preferential nucleation sites. The formation of these nucleation sites can be controlled by the sputtering parameters, allowing the control of nanowire density in a wide range. Nanowire nucleation is accompanied by unwanted parasitic islands, but by careful choice of annealing and growth temperature allows to strongly reduce the relative density of these islands and to realize samples with high nanowire yield.

We propose a method for generation of long-living autonomous fireball-like objects via a pulse erosive discharge between tin alloy electrodes. The objects are similar to the natural ball lightning in some properties, in particular, they have high energy density and are capable to burn through thin metal foils. The dynamics of the objects are studied using high speed videorecording. During their lifetime the fireballs generate aerogel threads. The studies of their structure by scanning electron microscopy reveal the presence of tin oxide nanoparticles and nanowhiskers., Comment: 8 pages, 6 figures. This is a preliminary version of our article, published in IJAER (see ref. below) with higher resolution images

The clean-up of several Creeks and Rivers by induction of a self-purification process was provided. The process took place at all the sites studied with the up to 100% resulted removal of polluting agents depending on the site and nature of the contaminant. The self-purification mechanism could be used for drinking and technical water preparation., Comment: 4 pages, 1 table, 5 references

A flotational mechanism of Etobicoke Creek's self-purification has been investigated. It is shown that the froth contains a high concentration of polluting agents. Chemical analyses of the top layer of surface water in comparison to both before and after froth collector in the course of a year are provided. As a result, the concentrations of pollutants by utilizing the model froth collector are decreased., Comment: 20 pages, 22 Graphs, 6 Tables, 19 References

The self-purification process of water streams is studied and the physical-chemical mechanism of it is determined. The naturally occurring self-purification process at the Boyne River site is monitored. Experiments at several creeks and rivers in GTA area that induced the self-purification process are provided. As a result, the concentration of polluting agents in the water decreases up to 100 % depending on the site and pollutants., Comment: 3 pages