The band-edge emission of CsPb₂Br₅ was located at 385 nm, not in the visible range as reported in the literature.

We report the syntheses of self-catalyst-grown and self-assembled ZnO nanoscrews (ZNS). The morphology and microstructures were characterized by using scanning electron microscopy, transmission electron microscopy and x-ray diffraction. The results reveal that the aligned ZNS are single crystalline grown along the $c$ axis, with 18 sides on their tops but six sides on their stems, while the whole exhibits sixfold symmetry. The formation of such a special-shaped ZNS that may have potential applications in fabrication of nanodevices, is related to the increase of the oxygen supply during the growth followed by a rapidly cooling down process. The growth kinetics of the ZNS is discussed. The field-emission studies show a good stability of the emission current and a low turn-on electrical field.