Nucleation-mediated growth of chiral 3D organic-inorganic perovskite single crystals.

Although their zero- to two-dimensional counterparts are well known, three-dimensional chiral hybrid organic-inorganic perovskite single crystals have remained difficult because they contain no chiral components and their crystal phases belong to centrosymmetric achiral point groups. Here we report a general approach to grow single-crystalline 3D lead halide perovskites with chiroptical activity. Taking MAPbBr (MA, methylammonium) perovskite as a representative example, whereas achiral MAPbBr crystallized from precursors in solution by inverse temperature crystallization method, the addition of micro- or nanoparticles as nucleating agents promoted the formation of chiral crystals under a near equilibrium state.

UV-vis-IR Broad Spectral Photodetectors Based on VO-ZnO Nanocrystal Films.

As a narrow band semiconductor at room temperature and a metallic material above ∼68 °C, functional VO films are widely investigated for smart windows, whereas their potential for ultraviolet-visible-infrared (UV-vis-IR) broad spectral photodetectors has not been efficiently studied. In this report, photodetectors based on VO-ZnO nanocrystal composite films were prepared by nanocrystal-mist (NC-mist) deposition. An enhanced photodetection switching ratio was achieved covering the ultraviolet to infrared wavelength.