Effects of alkylamine chain length on perovskite nanocrystals after washing and perovskite light-emitting diodes

摘要： Organic-inorganic hybrid lead halide perovskite nanocrystals (PeNCs) have great attention as a light source for perovskite light-emitting diodes (PeLEDs) owing to the superior optical properties. However, PeNCs typically use octylamine (OAm) as capping ligands which have insulating properties. Exploring a desirable short-alkylamine instead of OAm is required for the improvement of PeLEDs. Here, as a one of the strategies to solve this issue, the effects of alkylamine chain length for optical properties of PeNCs and PeLED characteristics are investigated. Pentylamine is an optimal short-alkylamine and precipitate luminescent PeNCs with high PLQY values of 90%. Importantly, pentylamine maintains a relatively high PLQY of 48% after spin-coating, due to the durability pentylamine has to ethyl acetate as a washing solvent. PeNCs capped with pentylamine also demonstrate an external quantum efficiency of over 1% with luminance of over 2000 cd/cm2, indicating that pentylamine has the potential to overcome the insulator properties of PeNC thin film.