Effects of surface passivation and rare earth doping on luminescence of double perovskite Cs2NaErCl6 materials

The Er 3+ -based double perovskite Cs 2 NaErCl 6 was successfully synthesized by the dissolve-dry method. The application of organic solvent passivation technology and rare earth doping technology addressed the issue of weak luminescence in perovskite materials. By using cyclohexane (CYH) and ethylene glycol (EG) as passivating agents, the intensity of upconversion luminescence (UCPL) in Cs 2 NaErCl 6 is increased by 240% and 127%, respectively. When Yb 3+ and Gd 3+ ions are incorporated into Cs 2 NaErCl 6 , the intensity of the green upconversion luminescence is increased by 17.1 and 12.3 times, respectively, compared to that of pure Cs 2 NaErCl 6 . The fluorescence enhancement of the former is attributed to the reduction of surface defects. The fluorescence enhancement of the latter may be attributed to the alteration of the upconversion mechanism. The efficient multi-modal luminescence characteristics show promising application potential in temperature sensing, semiconductor devices, anti-counterfeiting measures, and various other domains.