ABSTRACT
Lead halide perovskite single layers with three grain sizes are subjected to proton-beam irradiation in order to assess the durability and radiation tolerance of perovskite solar cells (PSCs) against space radiation. Proton-beam irradiation is chosen because proton beams significantly affect solar cell performance in the space environment. We evaluate the effects of proton beams by focusing on the grain structure, crystal structure, and carrier lifetime of a perovskite single layer by using scanning electron microscopy, X-ray diffraction, photoluminescence (PL) spectra, and time-resolved PL (TRPL). The results show that proton irradiation does not significantly affect the grain structure and crystal structure of perovskite layer; the TRPL results show that the carrier lifetime inside the grain is constant up to a fluence of 1 × 1014 p+/cm2 and decreases significantly at a fluence of 1 × 1015 p+/cm2. Proton-beam radiation tolerance of the grain inside the perovskite layer is dominant in the radiation tolerance of PSCs.
ABSTRACT
Materials to be used in the space environment have to withstand extreme conditions, particularly with respect to cosmic particle irradiation. We report robust stability and high tolerance of organolead trihalide perovskite solar cells against high-fluence electron and proton beams. We found that methylammonium and formamidinium-based lead iodide perovskite solar cells composed of TiO2 and a conductive polymer, as electron and hole transport materials, can survive against accumulated dose levels up to 1016 and 1015particles/cm2 of electrons (1 MeV) and protons (50 KeV), respectively, which are known to completely destroy crystalline Si-, GaAS-, and InGaP/GaAs-based solar cells in spacecraft. These results justify the superior tolerance of perovskite photovoltaic materials to severe space radiations and their usefulness in satellite missions.
ABSTRACT
Here we a report a rare case of extralimbic encephalitis associated with thymoma. A 66-year-old woman was admitted to our hospital with cramping in her right leg and inability to walk. Magnetic resonance imaging of the brain showed multifocal high intensity signals on T2 flare images in the cerebral cortex, and chest computed tomography showed a 5-cm anterior mediastinal mass, which was considered to be a thymoma. We speculated that she had paraneoplastic encephalitis associated with thymoma. She underwent a thymectomy and was diagnosed with type B1 thymoma. On postoperative day 6, her neurological symptoms began to improve. On postoperative day 31, she was discharged without complications. Limbic encephalitis is a paraneoplastic neurological syndromeassociated with thymoma, but extralimbic encephalitis has been described in the literature very rarely. We report the case of extralimbic encephalitis associated with thymoma along with a literature review.
