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Two-dimensional (2D) organic–inorganic perovskite hybrid materials with enhanced stability have attracted wide attention in optoelectronic field in recent years. Efforts of exploring new 2D perovskites with various organic or inorganic components have been devoted to further improve their solar cell efficiencies. In this work, three structurally similar spacer cations of phenylethylammonium (PEA), 4-bromophenylethylammonium (BPEA) and 4-chlorophenylethylammonium (CPEA) are selected to prepare multilayered 2D perovskites. It is found that the introduction of halogen atoms in the organic cations positively influences the film quality, light absorption, charge transport, device performance and moisture stability of the resulting perovskites. The (BPEA)2(MA)4Pb5I16 and (CPEA)2(MA)4Pb5I16 perovskites exhibit efficiencies of 7.38% and 10.88%, respectively, which are much higher than that of (PEA)2(MA)4Pb5I16 (3.98%). Owning to the larger size and bigger electronegativity of halogen atom in spacer cations, the PCE of unsealed BPEA- and CPEA-based 2D perovskite devices maintains 73% and 63% of their original efficiency after 720 h exposure to 60% humid air, while the PEA-based 2D device decreases to 52% of its initial PCE. Our work demonstrates new insight to modify the quality and stability of 2D perovskite hybrids, highlighting the validity of molecule design of organic cations in improving the efficiency and stability of 2D perovskite solar cells.

This paper systematically reviews the situation of joint combat intelligence support in recent local wars, and analyzes the experiences and lessons learned in the implementation of joint combat intelligence support in order to provide useful reference for the development of joint combat intelligence support for our military.

With the deepening of the new military transformation, cyberspace has become a battlefield without smoke. Network warfare is no longer a matter of talking on paper, but as a new combat style that can not only destroy enemy military command and control, intelligence information, and air defense military network systems, but also can quietly destroy, desecrate or even control the business of the other side. Civil affairs, government affairs, economic and trade, and other civil network systems have achieved the goal of fighting against the enemy without fighting. This paper studies and analyzes the development of the nine classic network warfare applications, and has important practical implications for shaping the safe and favorable cyberspace situation and advancing national cyberspace security.