Host-guest synergy of CH3NH3PbBr3@Ln-MOFs enabling tunable green luminescence and switchable memory

Metal organic frameworks (MOFs) contain ordered pores capable of encapsulating varied types of guests and provide a platform to expand the flexibility and versatility of the host-guest composites. Herein, by encapsulating CH3NH3PbBr3 NPS into Ln-MOFs (Ln = La, Nd, Pr, Sm), four CH3NH3PbBr3@Ln-MOFs host-guest composites were fabricated and served as a bifunctional platform. The temperature-dependent luminescence properties of the CH3NH3PbBr3@Ln-MOFs were explored and the results revealed their tuneable green luminescence perfor-mance. In particular, the CH3NH3PbBr3@Sm-MOF exhibits a variety of colours from green to blue to purple and an excellent quantum yield of 0.98. The photocurrent responses and theoretical calculations reveal the enhancement mechanism of CH3NH3PbBr3 on charge-hole separation owing to its unique host-guest synergy. Moreover, the CH3NH3PbBr3@Sm-MOF exhibits the excellent electrical bi-stability with a high ON/OFF ratio of 104. Hence, the CH3NH3PbBr3@Ln-MOFs host-guest composites are promising candidates for a new generation of photovoltaic, light-emitting, and switching memories devices.

Automated summary

By encapsulating CH3NH3PbBr3 NPS into Ln-MOFs, four CH3NH3PbBr3@Ln-MOFs host-guest composites with tunable green luminescence were fabricated. Among them, CH3NH3PbBr3@Sm-MOF exhibits a variety of colors and excellent quantum yield. The enhancement mechanism of CH3NH3PbBr3 on charge-hole separation and the excellent electrical bistability of CH3NH3PbBr3@Sm-MOF were revealed. Therefore, CH3NH3PbBr3@Ln-MOFs host-guest composites are promising candidates for next-generation photovoltaic, light-emitting, and switching memories devices.