Interfacial synthesis of SnTe/PbTe nanocrystals via cation diffusion

Arthur Shapiro sarthur@campus.technion.ac.il ¹ Youngjin Jang ¹ Yaron Kauffmann ² Faris Horani ¹ Efrat Lifshitz ¹

¹Schulich Faculty of Chemistry, Solid State Institute, Russell Berrie Nanotechnology Institute, Nancy and Stephen Grand Technion Energy Program, Technion–Israel Institute of Technology, Haifa, Israel
²Department of Materials Science and Engineering, Technion–Israel Institute of Technology, Haifa, Israel

Interface control by preparing heterostructures has been extensively studied for tuning electronic structure and getting intriguing optical properties. The present work demonstrates a facile preparation of SnTe/PbTe nanocrystals (NCs) in a solution-phase and their structural characterizations. Simple mixing of SnTe NCs with Pb reagents at low temperature led to the formation of PbTe shell as a sandwich layer between internal SnTe layer and external SnO₂ layer, by a cation diffusion of Pb²⁺ inwards. Elemental characterizations based on energy-dispersive X-ray spectroscopy confirmed the presence of PbTe ring layer and its evolution was tracked according to reaction conditions such as reaction time and temperature. Furthermore, a high temperature annealing process resulted in the breakage of the PbTe ring layer, showing large influence of temperature and dynamic characteristics of SnTe NCs` interface.