Morphologically controlled synthesis of ionic cesium iodide colloidal nanocrystals and electron beam-induced transformations

• Published in: RSC advances Vol. 8; no. 33; pp. 18519 - 18524
• Main Authors: Song, Weidong, Wu, Xiaotong, Di, Qian, Xue, Tianjiao, Zhu, Jichao, Quan, Zewei
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 01.01.2018; The Royal Society of Chemistry
• Subjects: Absorption spectra; Cadmium selenides; Cesium; Cesium iodides; Chemical bonds; Chemical synthesis; Chemistry; Colloid chemistry; Colloids; Covalent bonds; Electron beams; Electron irradiation; Energy gap; Gold; Medical imaging; Nanocrystals; Nanospheres; Optoelectronic devices; Particle physics; Photonic band gaps; Platinum; Silver; Stability; Transmission electron microscopy
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/c8ra02582g

Colloidal nanocrystals (NCs) have become an important group of novel materials with applications in various fields such as lighting, medicine, and optoelectronic devices. Compared to common semiconductor NCs ( , CdSe, CdS, PbS) with covalent bonds and metal NCs ( , Au, Ag, Pt) with metallic bonds, the synthesis of colloidal NCs with ionic bonds has rarely been explored, possibly due to their high solubility in polar solvents. In this work, we demonstrate a wet chemical synthesis route to prepare ionic cesium iodide (CsI) colloidal NCs, and they can be controllably made into different morphologies with good uniformity, including nanospheres, hexagonal nanoplates and nanocubes. The degradation of CsI NCs during transmission electron microscopy (TEM) has been investigated, revealing their sensitivity to high energy electron beam irradiation. The as-prepared CsI NCs exhibit strong absorption bands peaking at 275-280 nm, which should be ascribed to the presence of F-centers inside the band gap of CsI NCs. This study provides an efficient way to achieve controllable synthesis of high-quality CsI NCs that may find promising applications as advanced nanoscintillators in medical imaging, particle physics, position emission tomography and other various fields.