Probing the emissive behaviour of the lead-free Cs2AgBiCl6 double perovskite with Cu(ii) doping

Abstract

In the last few years, lead halide based perovskite materials have gained tremendous importance due to their excellent optical properties and easy synthesis procedure. But the poor stability of lead in the presence of heat, moisture, sun light and toxicity hinders the commercial applications of these materials. Therefore, lead-free double perovskite counterparts have achieved potential attention to overcome the instability and toxicity issues of lead halide perovskites. Lead-free inorganic halide double perovskites with high moisture, heat and light stable materials are explored in the last few decades as promising alternatives of toxic lead halide perovskites in the optoelectronic field. Herein, we have reported a solution-based synthesis of stable pristine and the Cu²⁺ doped Cs₂AgBiCl₆ double perovskite. Several characterization techniques, such as powered XRD, electron microscopic analysis, X-ray photon spectroscopy, and solid-state NMR, have been carried out to characterize both the bare and Cu doped double perovskites. EPR, SEM-EDX and ICP-MS studies confirm the presence of the Cu ion in the synthesized materials. Furthermore, the thermal stability is investigated along with the stability of the compounds under ambient conditions. We conclude that Cu doping leads to the quenching of fluorescence intensity gradually.