Hydrophobic–Hydrophilic Block Copolymer Mediated Tuning of Halide Perovskite Photosensitive Device Stability and Efficiency

Abstract

The polymer additive strategy provides a facile and cost-effective way for passivating defects and trap sites at the grain boundaries and interfaces and acting as a barrier against the external degradation factors in perovskite-based devices. However, limited literature exists discussing the integration of hydrophobic and hydrophilic polymer additives in the form of a copolymer within the perovskite films. The inherent difference in the chemical structure of these polymers and their interaction with perovskite components and the environment leads to critical differences in the respective polymer-perovskite films. The current work utilizes both homopolymer and copolymer strategies to understand the effect of polystyrene (PS) and polyethylene glycol (PEG), two common commodity polymers, over the physicochemical and electro-optical properties of the as-fabricated devices and the distribution of polymer chains across the depth of perovskite films. The hydrophobic PS integrated perovskite devices PS-MAPbI3, 36 PS-b-1.4-PEG-MAPbI3, and 21.5 PS-b-20-PEG-MAPbI3 outperform hydrophilic PEG-MAPbI3 and pristine MAPbI3 devices and exhibit higher photocurrent, lower dark currents, and greater stability. A critical difference is also observed in the stability of devices, where rapid decay of performance is observed in the pristine MAPbI3 films. The deterioration in performance is highly limited for hydrophobic polymer-MAPbI3 films as they maintain 80% of their initial performance.

A comprehensive review on the advancements and challenges in perovskite solar cell technology

“…The aim is to enhance the compactness and uniformity of the perovskite film, which includes reducing the number of defects such as pinholes and bolstering the intergranular connections. 146 These chemical and morphological modifications in the perovskite layer can substantially impact the performance of the device. A more compact and uniformly distributed perovskite film, achieved through the PAMAM interactions, facilitate improved charge separation and reduced recombination rates, thereby enhancing the overall stability and efficiency of the device.…”

Designed Polymer Ligands for Perovskite Quantum Dots and Their Block Copolymer Nanocomposites

“…There are two main approaches for the integration of BCPs with perovskite nanostructures. [ 28–30 ] The first one is based on introducing BCPs to perovskite precursors during nanoparticle synthesis, the BCPs act as polymer ligands or molecular templates for the synthesized perovskite nanoparticles. For instance, polystyrene‐ b ‐poly(2‐vinylpyridine) (PS‐ b ‐P2VP) has been directly mixed with MAPbBr 3 perovskite precursors to form hybrid structures after crystallization.…”