posted on 2020-03-18, 16:45authored byHao Liu, Xinyi Yang, Kai Wang, Yixuan Wang, Min Wu, Xiaobing Zuo, Wenge Yang, Bo Zou
Two-dimensional
(2D) nanomaterials have fascinating structural,
electrical, and optical properties, especially strong excitonic effects
due to decreased dielectric screening. However, constructing 2D ultrathin
nanomaterials, with the exception of layered materials, remains a
challenge. Herein, we successfully realize oriented attachment on
guiding one-dimensional chalcopyrite CuInS2 nanocrystal
(NC) formation and 2D assembly into lamellar nanosheets by applying
pressure-driven sintering of zero-dimensional CuInS2 nanoparticles
(NPs). We discuss the atomic-level mechanism of such phenomena and
illustrate a pressure-driven processing diagram that reveals the sintering
process of NPs coordinated by pressure and structural transformation.
Optical measurements exhibit that the band gap has a narrowing by
0.21 eV compared with the initial 2.03 eV upon decompression to ambient
conditions. Our findings represent a significant step forward in gaining
an in-depth understanding of the pressure-driven morphology engineering
of nanomaterials and provide a promising strategy to prepare 2D NCs,
thereby greatly increasing the choice of materials for various applications.