Open AccessShape Dependence of Pressure-Induced Phase Transition in CdS Semiconductor Nanocrystals
Author(s) -
Lingyao Meng,
J. Matthew D. Lane,
Luke Baca,
Jackie Tafoya,
Tommy Ao,
Brian Stoltzfus,
Marcus D. Knudson,
Dane Morgan,
Kevin Austin,
Changyong Park,
Paul Chow,
Yuming Xiao,
Ruipeng Li,
Yang Qin,
Hongyou Fan
Publication year - 2020
Publication title -
journal of the american chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.115
H-Index - 612
eISSN - 1520-5126
pISSN - 0002-7863
DOI - 10.1021/jacs.0c01906
Subject(s) - wurtzite crystal structure , phase transition , chemistry , phase (matter) , nanoparticle , chemical physics , bulk modulus , particle (ecology) , nanomaterials , transmission electron microscopy , nanotechnology , semiconductor , condensed matter physics , materials science , crystallography , composite material , optoelectronics , physics , organic chemistry , geology , oceanography , hexagonal crystal system
Understanding structural stability and phase transformation of nanoparticles under high pressure is of great scientific interest, as it is one of the crucial factors for design, synthesis, and application of materials. Even though high-pressure research on nanomaterials has been widely conducted, their shape-dependent phase transition behavior still remains unclear. Examples of phase transitions of CdS nanoparticles are very limited, despite the fact that it is one of the most studied wide band gap semiconductors. Here we have employed in situ synchrotron wide-angle X-ray scattering and transmission electron microscopy (TEM) to investigate the high-pressure behaviors of CdS nanoparticles as a function of particle shapes. We observed that CdS nanoparticles transform from wurtzite to rocksalt phase at elevated pressure in comparison to their bulk counterpart. Phase transitions also vary with particle shape: rod-shaped particles show a partially reversible phase transition and the onset of the structural phase transition pressure decreases with decreasing surface-to-volume ratios, while spherical particles undergo irreversible phase transition with relatively low phase transition pressure. Additionally, TEM images of spherical particles exhibited sintering-induced morphology change after high-pressure compression. Calculations of the bulk modulus reveal that spheres are more compressible than rods in the wurtzite phase. These results indicate that the shape of the particle plays an important role in determining their high-pressure properties. Our study provides important insights into understanding the phase-structure-property relationship, guiding future design and synthesis of nanoparticles for promising applications.