New Paper: in-situ Nucleation and Growth of Colloidal Quaternary Nanocrystals by Multimodal X-ray Analysis: Quick-EXFAS / XANES / SAXS
- Post by: jjust
- 2. April 2021
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In collaboration with the University of Limerick, Ireland and the Helmholtz-Zentrum Berlin, Germany, we recently published a study in ACS Nano where we combined time-resolved real time measurements of EXAFS, XANES and SAXS to investigate the nucleation and growth of CZTS (Cu2ZnSnS4) nano crystals.
Justus Just, Claudia Coughlan, Shalini Singh, Huan Ren, Oliver Müller, Pascal Becker, Thomas Unold, and Kevin M. Ryan
ACS Nano 2021, 15, 4, 6439–6447
DOI: https://doi.org/10.1021/acsnano.0c08617
Abstract: Copper chalcogenide nanocrystals find applications in photovoltaic inks, bio labels, and thermoelectric materials. We reveal insights in the nucleation and growth during synthesis of anisotropic Cu2ZnSnS4 nanocrystals by simultaneously performing in situ X-ray absorption spectroscopy (XAS) and small-angle X-ray scattering (SAXS). Real-time XAFS reveals that upon thiol injection into the reaction flask, a key copper thiolate intermediate species is formed within fractions of seconds, which decomposes further within a narrow temperature and time window to form copper sulfide nanocrystals. These nanocrystals convert into Cu2ZnSnS4 nanorods by sequentially incorporating Sn and Zn. Real-time SAXS and ex situ TEM of aliquots corroborate these findings. Our work demonstrates how combined in situ X-ray absorption and small-angle X-ray scattering enables the understanding of mechanistic pathways in colloidal nanocrystal formation.