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Halide perovskites have been proven to have enormous potential for further flexible optoelectronic devices. However, the repeated mechanical bending and tolerance to moisture corrosion remain a critical challenge for flexible perovskite devices. Solution chemistry of a precursor is the basis for the preparation of high-quality perovskite films and can significantly enhance the lasing performance and humidity stability of perovskites. Herein, from the perspective of solvent engineering, two ionic liquids (ILs) of methylammonium acetate (MAAc) and methylammonium propionate (MAP) were introduced to prepare high-quality MAPbBr3 perovskite films. The as-prepared MAPbBr3 perovskite films exhibit not only enhanced amplified spontaneous emission (ASE) performance but also the excellent mechanical reliability even in a humid environment. Especially, the MAAc-based MAPbBr3 perovskite film possesses the morphology optimization, defect passivation, simultaneous improvements in ASE, and bending durability due to the stronger coordination capacity and reactivity between MAAc and Pb2+. Our work provides an effective strategy for flexible perovskite based photonic devices fueled by the remarkable mechanical reliability. [ABSTRACT FROM AUTHOR]

For next-generation Internet-of-Everything applications, such as artificial neural-network image sensors, artificial retina, visible light communication, flexible devices, and so on, the photodetectors with excellent properties are urgently demanded. In recent years, two-dimensional (2D) material-based photodetectors have been developed and certified for remarkable performances. Nonetheless, it cannot meet the need of wide linear dynamic range, ultralow dark current, and large on/off ratio, which are critical factors for commercial applications. Recently, quasi-2D Ruddlesden–Popper (RP) perovskites are explored and developed as well-known photovoltaic and optoelectronic materials. Herein, an excellent photodetector based on quasi-2D RP layered perovskite PEA2FA2Pb3Br10 film was fabricated. The photodetector displays an ultralow dark current of 4.08 × 10−11 A, high specific detectivity of 1.69 × 1010 Jones, high on/off ratio of 7.33 × 103, and fast rise/fall times of 32/38 ms, attributed to its multiple quantum wells in PEA2FA2Pb3Br10. Therefore, the photodetectors based on quasi-2D RP perovskite PEA2FA2Pb3Br10 have immense potentials in the field of optoelectronics. [ABSTRACT FROM AUTHOR]

Nowadays, climate problems caused by greenhouse gases are becoming more and more serious. Motivated by reducing carbon dioxide emissions from fossil fuel power generation, scientists are devoting themselves to developing novel materials or technologies for capturing carbon dioxide. Nanostructure materials, which show great potential for this application, have come to the attention of scientists. Herein, the effects of doping an aluminum atom (replacing one boron atom by one aluminum one) on the adsorption of carbon dioxide on boron nitride nanosheets are theoretically investigated through computational analysis based on density functional theory. The results show that the binding between oxygen and aluminum atoms, which comes from classical Lewis base (CO2)-Lewis acid (Al) interactions, can provide a considerable gain to the mutual effect between the carbon dioxide molecule and the doped substrate. Compared with pristine boron nitride nanosheets, the adsorption energy value of the carbon dioxide molecule is markedly increased to 0.4784 eV (about 2.5-fold) after the doping process, which is in the range of the ideal adsorption energy of 0.415-0.829 eV. More importantly, the essence of physisorption signifies that carbon dioxide can be released by means of specific physical desorption, and, sequentially, this is more conducive for achieving reversible adsorption.