Off-Stoichiometric Methylammonium Iodide Passivated Large-Grain Perovskite Film in Ambient Air for Efficient Inverted Solar Cells.

Hot-casting is a promising technique of depositing high-quality organic-inorganic hybrid perovskite thin films with large crystal grain size. Here, we reported the that the crystallinity and grain size of perovskite films could be systematically tailored by modulating the stoichiometry of the precursor solution in the hot-casting process under ambient condition with a relative humidity of 40%. It was found that a slight excess of methylammonium iodide (MAI) in the precursor solution could effectively compensate the MAI loss due to the high substrate temperature.

Shielding analysis at the upper section of the accelerator-driven system.

The proton beam duct of the accelerator-driven system (ADS) acts as a streaming path for spallation neutrons and photons and causes the activation of the magnets and other devices above the subcritical core. We have performed a streaming analysis at the upper section of the lead-bismuth target/cooled ADS (800 MWth). MCNPX was used to calculate the radiation dose from streamed neutrons and photons through the beam duct.