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The influence of the synthesis conditions (rotation speed used for spin-coating deposition of the film, film drying temperature, and the ratio of the PbI2 and CH3NH3I reactants in solutions) on the microstructure, phase composition, and spectral-luminescent properties of films of organic-inorganic perovskite CH3NH3PbI3-xClx (x = 0, 0.02) was elucidated. [ABSTRACT FROM AUTHOR]

The influence of the synthesis conditions (rotation speed used for spin-coating deposition of the film, film drying temperature, and the ratio of the PbI2 and CH3NH3I reactants in solutions) on the microstructure, phase composition, and spectral-luminescent properties of films of organic-inorganic perovskite CH3NH3PbI3-xClx (x = 0, 0.02) was elucidated. [ABSTRACT FROM AUTHOR]

In this paper, we present a study of the structural and optical properties of organic–inorganic halide-based perovskite semiconductors with band gaps varying from NIR to visible at room temperature. Thin films of nanocrystalline CH 3 NH 3 PbI 3 with different concentrations of methylammonium iodide (MAI) have been successfully deposited onto glass substrates using single step spin-coating technique. The prepared films have been characterized by X-ray diffraction, optical absorption spectroscopy and photoluminescence measurements. X-ray diffraction scans revealed that even for stoichiometric atomic concentrations of MA:Pb:I of 1:1:3, the PbI 2 phase was also present. The PbI 2 phase showed a highly textured along the (001) direction in all the prepared films, with a crystallite size in the range of approximately 30–40 nm. The optical absorbance edge of CH 3 NH 3 PbI 3 thin films is described in terms of direct transition model proposed by Tauc in the strong absorption region. The band gap of the pure PbI 2 film was calculated to be 2.40 eV, whereas the band gap of the pervoskite film with stoichiometric ionic ratio of 1:1 PbI 2 and CH 3 NH 3 I was calculated to be 1.46 eV, while absorption coefficient is ~10 5 cm −1 . Photoluminescence measurements showed a red shift in the perovskite emission with increasing the MAI concentration, confirming the correct placement of the MA ions in the perovskite crystalline structure showing the PbI 2 octahedra. Our results confirm the existence of PbI 2 phase in the highly efficient perovskite solar cells, as demonstrated in the recent publication. [ABSTRACT FROM AUTHOR]

The Luminescent solar concentrators (LSCs) consist of a film containing optically active centers, converting part of the absorbing radiation into a specific emitting wavelength, when exposed to sunlight. The emitting centers are also crucial factors regarding their efficiency, so the selection must be done carefully. Here, we introduce organometal halide perovskite as a new class of phosphors, to use in luminescent solar concentrators. The coating of a Si PV cell with an organometal halide perovskite is tested. The obtained results reveal that, to find a suitable condition for effective LSC, it is necessary to determine appropriate molar ratio of organic and inorganic portion in synthesis perovskite, as well as concentration of halide perovskite in LSC. It is found that CH 3 NH 3 PbBr 3 perovskite with the CH 3 NH 2 /PbBr 2 : 6/1 M ratio and 7.0 wt% perovskite concentration in Polyvinyl Alcohol (PVA) leads to the highest efficiency (increased about 45%, compared to uncoated cell). [ABSTRACT FROM AUTHOR]