Nanosized molecular clusters (MCs) composed of PbBr2 and neutral ligand butylamine (BTYA) with unique optical properties in solution and solid states have been synthesized using ligand-assisted reprecipitation and spin-coating, separately. The studies of their optical properties using ultraviolet–visible (UV−vis) absorption and photoluminescence (PL) show the first electronic absorption and PL band of the MCs at 401 and 411 nm, respectively, for the solution and solid state samples that exhibit good stability under ambient conditions. Low-temperature PL spectra below 30 K show vibronic peaks indicative of a single size or a very narrow size distribution of the MCs. On the basis of Raman, X-ray diffraction, and transmission electron microscopy measurements, a layered structural model is proposed for the MCs with a BTYA ligand capping on the surface of the corner-shared tilted [PbBr6]4– octahedral framework. The stable and retained structure of MCs in the solid state is promising for photonics applications.

are driven by human life support systems, scientific exploration and Earth observation equipment, telecommunications, and electric propulsion systems. There is great interest in highly efficient perovskite-structured thin-film solar cells for space applications. [1,2] These are promising candidates due to their excellent optoelectronic characteristics, low-cost, high performance, [2][3][4] and their facile manufacturability [5] potentially suitable for in-space manufacturing. [6] These traits coupled with their defect tolerance, [7,8] and radiation tolerance [9] have garnered interest for aerospace applications. Prior to the widespread implementation of metal halide perovskites (MHPs) into the space environment, solar cells must pass rigorous American Institute of Aeronautics and Astronautics Standard 111 (AIAA-S111) space qualification testing. [10] Low earth orbit (LEO), 160-2000 km above the Earth's surface, is an ideal place to operate MHPs either on the International Space Station or on satellites. The harsh environment of LEO includes thermal cycling (±120 ⁰C), vacuum (10 −6 -10 −9 torr), ultra-violet radiation, exposure to atomic oxygen (flux 10 13 -10 15 AO/cm 2 with collision energy of 5 eV), plasma (10 6 cm −3 , ≤1 eV electron temperature), and ionizing radiation of electrons, protons, micrometeoroids (60 km s −1 ) and orbital debris (10 km s −1 ). [11] We must demonstrate MHP durability in relevant space environments to evidence feasibility. Implementing Metal halide perovskites (MHPs) have emerged as a prominent new photovoltaic material combining a very competitive power conversion efficiency that rivals crystalline silicon with the added benefits of tunable properties for multijunction devices fabricated from solution which can yield high specific power. Perovskites have also demonstrated some of the lowest temperature coefficients and highest defect tolerance, which make them excellent candidates for aerospace applications. However, MHPs must demonstrate durability in space which presents different challenges than terrestrial operating environments. To decisively test the viability of perovskites being used in space, a perovskite thin film is positioned in low earth orbit for 10 months on the International Space Station, which was the first long-duration study of an MHP in space. Postflight high-resolution ultrafast spectroscopic characterization and comparison with control samples reveal that the flight sample exhibits superior photo-stability, no irreversible radiation damage, and a suppressed structural phase transition temperature by nearly 65 K, broadening the photovoltaic operational range. Further, significant photo-annealing of surface defects is shown following prolonged light-soaking postflight. These results emphasize that methylammonium lead iodide can be packaged adequately for space missions, affirming that space stressors can be managed as theorized.

Aerospace In article number 2203920, Lyndsey McMillon‐Brown, Sayanatani Ghosh, and co‐workers report on the first long duration space flight of a metal halide perovskite photoactive layer on the International Space Station. Post‐flight analysis reveals that samples exhibit superior photo‐stability, no irreversible radiation damage, and a suppressed structural phase transition temperature, broadening the photovoltaic operational range. These results confirm that perovskite photovoltaics can be designed to endure the space environment.