Bernal Institute, University of Limerick , Limerick V94 T9PX, Ireland.
ACS Appl Mater Interfaces. 2018 Feb 28;10(8):7117-7125. doi: 10.1021/acsami.7b18711. Epub 2018 Feb 14.
Here, we report the first detailed investigation into the selenization mechanism of thin films of wurtzite copper zinc tin sulfide (CZTS) nanorods (NRs), giving particular emphasis to the role of the long-chain organic ligands surrounding each NR. During selenization, the NRs undergo a selenium-mediated phase change from wurtzite to kesterite, concurrent with the replacement of sulfur with selenium in the lattice and in situ grain growth, along with the recrystallization of larger copper zinc tin selenide kesterite grains on top of the existing film. By utilizing a facile ligand removal technique, we demonstrate that the formation of a large-grain overlayer is achievable without the presence of ligands. In addition, we demonstrate an elegant ligand-exchange-based method for controlling the thickness of the fine-grain layer. This report emphasizes the key role played by ligands in determining the structural evolution of CZTS nanocrystal films during selenization, necessitating the identification of optimal ligand chemistries and processing conditions for desirable grain growth.
在这里，我们首次详细研究了纤锌矿铜锌锡硫（CZTS）纳米棒（NRs）薄膜的硒化机制，特别强调了围绕每个 NR 的长链有机配体的作用。在硒化过程中，NRs 经历了硒介导的从纤锌矿到黄铜矿的相变，同时晶格中的硫被硒取代，以及原位晶粒生长，以及在现有薄膜上形成更大的铜锌锡硒黄铜矿晶粒的再结晶。通过利用一种简便的配体去除技术，我们证明了在没有配体的情况下可以实现大晶粒覆盖层的形成。此外，我们还展示了一种基于配体交换的优雅方法来控制细晶粒层的厚度。本报告强调了配体在决定 CZTS 纳米晶薄膜在硒化过程中的结构演变中所起的关键作用，这需要确定合适的配体化学和处理条件以实现理想的晶粒生长。
