Ultrabroadband Emission from CsCu2I3/Cs3Cu2I5 Dual-Phase Glass-Ceramics with Long-Term Stability

Metal halides (MHs) show great potential in photovoltaic and optoelectronic applications, but their lack of long-term stability limits their applications for their sensitivity to oxygen, moisture, strong light irradiation, and high temperature. In this report, lead-free MHs CsCu2I3/Cs3Cu2I5 dual-phase glass-ceramics were prepared with a traditional melting-quenching method by using solid reductive agent Si3N4. Ultrabroadband emission from violet to near-infrared (350–800 nm) can be obtained from these CsCu2I3/Cs3Cu2I5 dual-phase glass-ceramics with long-term water-resistance stability. Detailed analysis of microstructure, spectra, and calculation reveals that the ultrabroadband nature can be ascribed to the intense emission of CsCu2I3 NCs, Cu+ ions, and Cs3Cu2I5 NCs together, and especially, the emission from Cs3Cu2I5 NCs and Cu+ ions presents a cyan color. Our work not only demonstrates that CsCu2I3/Cs3Cu2I5 glass-ceramic is a promising fluorescent material, but also develops a method to prepare lead-free metal halides CsCu2I3/Cs3Cu2I5 dual-phase glass-ceramics with high stability, paving the way for their applications.