Rational design of organic–inorganic metal halide perovskites and encapsulation via metal–organic frameworks as a stable platform with improved deep blue emission

Abstract

The primary challenge facing perovskite nanocrystals (PNCs) is their stability, which hinders their potential impact on the industry. This study focuses on new organic–inorganic metal halide perovskites (OIMHPs) with stable deep blue emission using the beneficial encapsulation aspects of metal–organic frameworks (MOFs). Novel (Et)3NHPbBr3 PNCs with deep blue emission were synthesized via the facile ligand‐assisted reprecipitation (LARP) technique. To address both stability issues and low emission efficiency, the (Et)3NHPbBr3 PNCs were effectively embedded within zinc‐based mesoporous MOF‐5 structures. The pore structure of MOF‐5 microporous (with pores size of 1.68 nm) was initially modified to mesoporous (M3 with pores size of 36.88 nm) to facilitate the localization of PNCs inside MOF pores. Then, a full series of experimental parameters were optimized, which resulted in about 10‐fold enhancement in photoluminescence quantum efficiency (PLQE) from 6% for the bare (Et)3NHPbBr3 PNCs to 58% for the (Et)3NHPbBr3@MOF‐5 composite with emission signal located at around 394 nm. The emission stability of the fabricated composite was also investigated against external conditions and showed that the optimized composite has an excellent emission after 180 days of storage in environmental conditions, along with a preserved PL emission at elevated temperatures up to 100 °C. This study presents a straightforward and cost‐effective method for producing novel deep‐blue emissive (Et)3NHPbBr3 PNCs encapsulated within MOFs, showcasing substantial improvements in PLQE and stability that are crucial for the development of efficient optoelectronic devices.