Low-Reflection, (110)-Orientation-Preferred CsPbBr3 Nanonet Films for Application in High-Performance Perovskite Photodetectors

All-inorganic metal halide perovskites have caught great interest in recent years due to their good device performance with higher thermal stability than 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 benefits for the charge carrier transport and the light-harvesting efficiency. The (110) peak intensity of CsPbBr3 NFs increased with increasing the diameter of the monolayer sphere, while the (001) peak intensity was suppressed greatly, indicating the more preferred (110) orientated 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, the responsivity and detectivity of 2.84 A W-1 and 5.47×1012 Jones were also achieved.