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Nickel oxide (NiO) is one of the most promising and high-performing Hole Transporting Layer (HTL) in inverted perovskite solar cells due to ideal band alignment with perovskite absorber, wide band gap, and high mobility of charges. At the same time, however, NiO does not provide good contact and trap-free junction for hole collection. In this paper, we examine this problem by developing a double hole transport configuration with a copper iodide (CuI) interlayer for efficient surface passivation. Transient photo-current (TPC) measurements showed that Perovskite/HTL interface with CuI interlayer has an improved hole injection; CuI passivation reduces the concentration of traps and the parasitic charge accumulation that limits the flow of charges. Moreover, we found that CuI protect the HTL/perovskite interface from degradation and consequently improve the stability of the cell. The presence of CuI interlayer induces an improvement of open-circuit voltage VOC (from 1.02 V to 1.07 V), an increase of the shunt resistance RSH (100%), a reduction of the series resistance RS (−30%), and finally a +10% improvement of the solar cell efficiency.

Exchange-coupled nanocomposites are considered as the most promising materials for production of high-energy performance permanent magnets, which can exceed neodymium ones in terms of energy product. In this work, micromagnetic simulations of L1 0-FeNi/SmCo 5 composites based on the initially anisotropic structure of nanorods array were performed. Texturing effect on magnetic properties was investigated. It was revealed that even 30 % of anisotropy axes misalignment of grains in L1 0-FeNi phase would lead to only  10 % drop of coercivity. To maximize magnetic properties of the composites, parameters of microstructure were optimized for 120 × 120 array of interacting nanorods and were found to be 40 nm nanorod diameter and 12-20 nm interrod distance. The estimated diameter of nanorods and the packing density of the array provide energy product values of 149 kJ m-3. Influence of interrod distance on energy product values was explored. Approaches for production of exchangecoupled composites based on anisotropic nanostructures were proposed.

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Trihalide perovskite photovoltaic (P-PV) solar cells have a promise to be connected into tandems with inorganic PV systems. In this paper, we present p-i-n GaAs & P-PV cells in either in a series way or parallel connection. Comparisons made for two types of tandems by a non-monolithic connection of two experimental sub-cells and results are being discussed based on simulation analysis. It is shown that the parallel connection is always preferable when the sub-cells photocurrent is not balanced while V oc (open circuit voltage) is close to each other. Total efficiency over 20% is demonstrated for GaAs shading effect by MAPbI 3 (methylammonium lead halide) film, with achieved J sc -41 mA/cm 2 (short circuit current density) and high V oc.