Lead Halide Perovskite Nanocrystals: Stability, Surface Passivation, and Structural Control

Lead halide (LH) perovskites have received enormous attention recently because of their interesting optoelectronic properties and high power conversion efficiency (PCE) in photovoltaic solar cells. However, material instability toward factors such as water, UV light, temperature, and oxygen have presented a major challenge for practical applications. Recently, LH perovskite nanocrystals (PNCs) have also drawn increasing attention owing to their tunable optical properties and ability to serve as model systems for studying the mechanism of material instability or degradation. Surface passivation of PNCs is critical to achieving high stability and desired optical properties. In this review, we highlight several surface passivation strategies developed for improving the stability of LH perovskites and synthesizing PNCs with different morphologies as a promising class of materials for photovoltaics, light‐emitting diodes (LEDs), and sensing applications.