High-entropy perovskite quantum dots of rare earth synergy with excellent luminescence stability via high-energy ball milling

Abstract

The problem of low stability and high lead content limit the commercial development of halide perovskite. In this paper, the high-energy ball milling is used to rapidly and efficiently synthesize high-entropy Cs(Pb1/5Mn1/5Ni1/5Zn1/5Yb1/5)Cl3 quantum dots (QDs), the introduction of high-entropy and rare earth ions reduces lead content, increases mixing entropy, and synergistically enhances the photoluminescence (PL) intensity and stability of QDs with other ions. Because the increase of entropy enhances the stability, the QDs still have 70 % PL intensity after 60 days of placement. After the QDs are exposed to the ultraviolet lamp for 8 hours, the PL intensity maintains at 67.1 % due to the loss of ligand. Ionic bonds are easily broken in water, so after soaking in water for 8 hours, the PL intensity of the QDs keeps at 32 %. The thermal stability of QDs is maintained well because of physical and chemical stability of rare earth ions. Since ethanol dissolves the ligands on the surface of the QDs, the non-radiative recombination is enhanced, so the PL intensity of QDs remains at 59 % after soaking for 8 hours. This paper provides a new way that further enhances the stability and solves high lead content of all-inorganic perovskite materials.