“Lead-free” perovskite colloidal nanocrystals for highly performing photonic and optoelectronic devices

In the last years, perovskite colloidal nanocrystals have gained attention because of their outstanding optical properties. Their widespread is, however, curbed by their lead-based composition. So-called “double perovskites” overcome this issue by substituting the lead atoms with lighter and non-toxic elements such as silver, sodium and bismuth. Despite the growing applicative interest, to date, the performance of double perovskite nanocrystals are lagging substantially behind their lead-based analogues. The paper “Compositional Tuning of Carrier Dynamics in Cs₂Na_1–xAg_xBiCl₆ Double-Perovskite Nanocrystals” (doi: 10.1021/acsenergylett.0c00914), published in the journal ACS Energy Letters (Impact factor 16.331 - 2018 Journal Impact Factor, Journal Citation Reports - Clarivate Analytics, 2019) produced by the collaboration between the research group led by Prof Sergio Brovelli of the Department of Materials Science of the University of Milano - Bicocca and the teams led by Liberato Manna and  Ivan Infante of the Italian Institute of Technology combines structural, theoretical and spectroscopic experiments to obtain in-depth understanding of the electronic processes of Cs₂Na_1−xAg_xBiCl₆ nanocrystals. The obtained compositional guidelines are important for the optimization of double perovskite nanostructures in view of their application in high performance optoelectronic and photonic devices.