Synergistic effect of Manganese stearate encapsulating CsPbI3 perovskite quantum dots with high phase stability

Abstract

Inorganic cesium lead halide perovskite quantum dots (CsPbX₃ PQDs, X= Cl, Br or I) have drawn great attention because of their superb optoelectronic properties. However, the phase transition from cubic to orthorhombic accelerates the degradation of CsPbI₃ PQDs, resulting in poor stability. Here, we proposed a facile method to encapsulate CsPbI₃ PQDs in manganese stearate (MnSt₂, C₃₆H₇₀MnO₄) powder, in which Mn²⁺ is introduced into CsPbI₃ crystal to increase the tolerance factor, leading to suppress phase transition. The presence of MnSt₂ not only serves as a hydrophobic matrix to protect CsPbI₃ PQDs from the surrounding environment but also passivates the surface of PQDs. Benefiting from the synergistic effect of MnSt₂, the as-synthesized CsPbI₃-MnSt₂ nanocomposites exhibit enhanced phase stability in ambient conditions for more than 180 days. Furthermore, a white light-emitting diode (WLED) with excellent performance was constructed, demonstrating that encapsulation of PQDs with MnSt₂ represents a valid strategy to stabilize CsPbI₃ PQDs toward optoelectronic application.