In-situ fabricated poly (vinylidene fluoride)-Incorporated perovskite nanocrystals with better Schottky performance and enhanced stability

Abstract

The inherent defect states in perovskite nanocrystals (PNCs) have been known to cause degradation in device performance. Hydrophobic polymers with long chained repeating units are frequently employed as protecting layers to passivate the perovskite surface and improve their performance and stability. Here, we report the preparation and Schottky analysis of Formamidinium lead halide PNCs incorporating polyvinylidene fluoride (PVDF) as an additive. The structural characterization of the polymerized compounds confirms the formation of PNCs with better crystallinity and larger grains. The PVDF- incorporated samples (PVDF/PNCs) showed enhanced absorption in the entire visible region along with a decrease in non-radiative recombination events confirmed from dynamic PL studies. In consequence, the PVDF/PNCs Schottky device reveals better electrical performance with higher values of rectification and ideality factor close to unity. Also, from the C–V analysis of the devices, an almost 5-fold increase in carrier concentration is observed. Additionally, the thermal stability of the polymerized PNCs samples improved owing to the interaction between the organic cation and the polymer functional group. This study provides a new design strategy for interface engineering by PVDF incorporation into PNCs that can improve device performance and stability.