Moisture-Induced Degradation of Quantum-Sized Semiconductor Nanocrystals through Amorphous Intermediates
Hyeonjong Ma, Sungsu Kang, Seunghan Lee, Gisang Park, Yuna Bae, Gyuri Park, Jihoon Kim, Li Shi, Hayeon Baek, Hyeongseung Kim, Jong‐Sung Yu, Hoonkyung Lee, Jungwon Park, Jiwoong Yang
Abstract
Elucidating the water-induced degradation mechanism of quantum-sized semiconductor nanocrystals is an important prerequisite for their practical application because they are vulnerable to moisture compared to their bulk counterparts. In-situ liquid-phase transmission electron microscopy is a desired method for studying nanocrystal degradation, and it has recently gained technical advancement. Herein, the moisture-induced degradation of semiconductor nanocrystals is investigated using graphene double-liquid-layer cells that can control the initiation of reactions. Crystalline and noncrystalline domains of quantum-sized CdS nanorods are clearly distinguished during their decomposition with atomic-scale imaging capability of the developed liquid cells. The results reveal that the decomposition process is mediated by the involvement of the amorphous-phase formation, which is different from conventional nanocrystal etching. The reaction can proceed without the electron beam, suggesting that the amorphous-phase-mediated decomposition is induced by water. Our study discloses unexplored aspects of moisture-induced deformation pathways of semiconductor nanocrystals, involving amorphous intermediates.