Colloidally Synthesized Near-Infrared-Emitting Perovskite Nanocrystals for Optoelectronics

Near-infrared (NIR) light emitting nanocrystals possess spectacular optoelectrical properties, which play pivotal roles in photonics, optical devices, and nanomedicine. The advent of halide perovskites (HPs) has marked a significant development in the applications of NIR-emitting nanocrystals in optoelectrical devices. Given the potential of NIR-perovskite in photovoltaics applications, there has been a growing focus on developing colloidal HP nanostructures for both fundamental study and commercial applications. These optoelectronic applications require the solution-processability and compatibility of these nanocrystal (NC) emitters in various organic and inorganic matrices. Colloidal synthesis of NCs facilitates these requirements, ushering in a new era of research on the architecture of HP nanostructures, which has yet to unfold many unresolved fundamental mysteries. This review examines recent studies on NIR-light-emitting undoped and doped all-inorganic and hybrid HP colloidal NCs with or without toxic lead and meticulously analyzes the role of surface ligands in the synthesis, crystallographic phase, and colloidal stability of these HP nanocrystals. The review particularly focuses on the recent progress in the synthesis, photophysics, excited-state carrier dynamics, and environmental stability of these NIR-perovskite NCs and their applications in the fabrication of optoelectronic devices, including NIR-LEDs, solar cells, photodetectors, and luminescent solar concentrators.