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Multi-UAV enclosing has become one of the important attack methods in modern air combat. Recently, the algorithms of multi-UAV enclosing have been extensively studied to improve the formation speed of multi-UAV enclosing and improve the robustness. However, these algorithms fail to consider the impact of sensor failure on UAV, nor do consider the formation convergence speed at the initial stage of multi-UAV enclosing. Aiming at these problems, a method of multi-target assignment and multi-UAV enclosing based on competition and cooperation mechanism is proposed.Firstly, the competition mechanism is analysed, and the multi-target assignment method based on the competition mechanism is designed to improve the formation convergence speed.Secondly, a multi-UAV enclosing method is designed based on the cooperation mechanism.The method transforms the topology of the UAV to obtain the formation when the detection failure or communication failure happens. In the simulation, the designed method can form the enclosing formation faster, and has stronger robustness when the detection failure or communication failure happens.

Organic–inorganic metal halide perovskites have achieved great success in applications such as light-emitting diodes, photodetectors (PDs) and solar cells due to their high light absorption coefficients, tunable band gaps and simple solution-process technologies. However, their polycrystalline films have low carrier mobility and high defect states, which limit the device performance. As substitutes, perovskite microcrystal (MC) films exhibit higher carrier mobility and lower defect state density and thus, they have received much attention in recent years. Herein, we introduce MAPbX3 (X = Br, I) MC films with controllable thickness and adjustable band gap, and the self-powered MAPbI3 perovskite MC PDs (MCPDs) with a structure of ITO glass/perovskite MC film/carbon have been assembled for the first time. By optimizing the thickness of the MC film, our hole-transport-layer-free (HTL-free) PDs exhibit excellent self-powered performance, with an on/off ratio as high as 2 × 105, the rise/fall time of 80/580 μs, the responsivity of 0.26 A W−1, the detectivity of 7.01 × 1011 Jones and the linear dynamic range of 107 dB. In addition, our MCPDs without encapsulation show excellent light and storage stability. These results indicate a good method for preparing high-performance and high-stability perovskite MC devices. [ABSTRACT FROM AUTHOR]

Owing to good crystal structure and novel one-dimensional (1D) outer surface, MAPbI3 nanowires (NWs) show fewer grain boundaries, lower defect density and longer carrier lifetime as compared with their polycrystalline thin films, leading to MAPbI3 NWs exhibiting higher quantum efficiencies in optoelectronic devices. Herein, by a simple two-step spin-coating method with the addition of various N,N-dimethylformamide (DMF) contents, a PbI2–DMF adduct is formed; this changes the micro-morphology of MAPbI3 perovskite from 3 dimensional (3D) nanocubic to 1D NW. Through optimizing the DMF contents, MAPbI3 NWs with strongest light absorbability and best crystallinity have been obtained (500 μL DMF). In addition, photodetectors (PDs) are assembled with various DMF amounts on glass substrates, and the optimal MAPbI3 NW PD (500 μL DMF) shows the best performance with on/off ratio greater than 250; the rise and decay times are 12 and 22 ms, respectively. Furthermore, a flexible MAPbI3 NW PD is assembled, and it shows good sequential and stable response with the on/off ratio of more than 45. Notably, under various bending curvatures and many cycles, the performance of the flexible NW device has only slight degradation. Our results may have great value for the application of flexible MAPbI3 NW devices in the future. [ABSTRACT FROM AUTHOR]

Self-powered light-emitting photodetectors (SLEPs) can simultaneously transmit and receive information using light, offering huge potential for applications in interactive communication systems. However, high-performance SLEPs are very hard to achieve due to the seriously contradictory principles of carrier transport in SLEPs. In this study, a novel structure based on a ZnO hollow ball/CsPbBr3 heterojunction, in which ZnO hollow balls function as an ultraviolet (UV) response center and CsPbBr3 is designed to be a green light-emitting material, is reported as a high-performance SLEP. Since the ZnO hollow balls have superior light trapping characteristics for UV light, the device shows a huge UV response with the on/off ratio and detectivity up to 16 527 and 2.4 × 1013 Jones, respectively. Moreover, it displays blue emission with a low threshold voltage because of CsPbBr3. Compared with the traditional ZnO/GaN structure devices, the device showed enhanced dual-functional performance at various wavelengths due to the insertion of CsPbBr3, which resulted in a better contact interface and green-light emission center. Our structure separating the light-responsive and emitting active regions avoids the contradictory principles of carrier transport, which may provide new access to gain high-performance dual-functional devices. [ABSTRACT FROM AUTHOR]

All‐inorganic halide perovskite is considered as outstanding candidate of organic–inorganic hybrid perovskite due to its superior stability. However, the low solubility of precursor and uncontrollable film growth result in poor film quality and impede the application of polycrystalline films greatly. In this work it is reported on a space‐confined growth strategy to overcome the low solubility and fast crystal growth disadvantages via freezing the precursor solution within the gaps of ordered polystyrene sphere templates. Then, the dense CsPbBr3 polycrystalline films realize low trap density (3.07 × 1012 cm−3) and high carrier mobility (9.27 cm2 V−1 s−1) after stoichiometric modulation. Photodetectors based on these films exhibit high performance in all figures of merit. Specifically, high responsivity up to 216 A W−1 and ultrashort response time (<5 µs) are achieved, which are better than those of all the CsPbBr3 based PDs. A record detectivity of 7.55 × 1013 and 3.1 × 105 Hz −3 dB bandwidth are also achieved. This work opens the window of high quality all‐inorganic halide perovskite polycrystalline films and can be extended to rational application of more optoelectronic devices including solar cells, photoelectrodes, and ray detectors. A space‐confined growth strategy is applied to overcome the low solubility and fast crystal growth disadvantages of CsPbBr3 polycrystalline films. The dense films can realize low trap density and high carrier mobility after stoichiometric modulation. Photodetectors based on these films exhibit high performance in all figures of merit, such as detectivity, linear detection range, and response time. [ABSTRACT FROM AUTHOR]

All-inorganic metal halide perovskites have attracted great interest in recent years due to their good device performance with higher thermal stability than that of their organic-inorganic perovskite counterparts. However, the all-inorganic perovskite polycrystalline films prepared by the conventional spin-coating method possess many pinholes, nonuniform surface with many small crystals, and irregular agglomerates, limiting their device performance. Herein, we introduced a monolayer nano-polystyrene (PS) sphere confined growth method for obtaining CsPbBr3 nanonet films (NFs) with ordered nanostructures grown in the preferred (110) orientation, which is beneficial for the charge carrier transport and the light-harvesting efficiency. The (110) peak intensity of CsPbBr3 NFs increased with the increase of the diameter of the monolayer sphere, while the (001) peak intensity was suppressed greatly, indicating the more preferred (110) oriented growth. The PDs based on (110)-orientation-preferred CsPbBr3 NFs prepared by using 850 nm PS spheres showed the best performance. The best performing device displayed the biggest linear dynamic range of up to 120 dB. In addition, a responsivity of 2.84 A W-1 and a detectivity of 5.47 × 1012 Jones were also achieved.