So far, most techniques for modifying perovskite solar cells (PSCs) focus on either the perovskite or electron transport layer (ETL). For the sake of comprehensively improving device performance, a dual‐functional method of simultaneously passivating trap defects in both the perovskite and ETL films is proposed that utilizes guidable transfer of Eu3+ in SnO2 to perovskite. Europium ions are distributed throughout the SnO2 film during the formation process of SnO2, and they can diffuse directionally through the SnO2/perovskite interface into the perovskite, while most of the europium ions remain at the interface. Under the synergistic effect of distributed Eu3+ in the SnO2 and aggregated Eu3+ at the interface, the electron mobilities of ETLs are evidently improved. Meanwhile, diffused Eu3+ ions passivate the perovskite to reduce trap densities at the grain boundaries, which can dramatically elevate the open‐circuit voltage (Voc) of PSCs. Finally, the mainly PSCs coated on SnO2:Eu3+ ETL achieve a power conversion efficiency of 20.14%. Moreover, an unsealed device degrades by only 13% after exposure to ambient atmosphere for 84 days.

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Abstract:In this work, racemic hybrid polypeptides poly(ethylene glycol) (PEG)-bpoly(racemic-leucine) (PRL) copolymers with different leucine residues have been synthesized and characterized. Using docetaxel as a model molecule, the high drug-loaded spherical micelles based on PEG-PRL were prepared successfully using dialysis, with a tunable particle size from 170 nm to 250 nm obtained by changing the length of the hydrophobic blocks. Facilitated drugloading behavior (higher drug-loading ability and easier drug-loading process) of PEG-PRL compared with their corresponding levo forms (PEG-b-poly[levo leucine]) was observed and clarified for the first time. With this facilitation, the highest drug-loading content and efficiency of PEG-PRL micelles can achieve 11.2% ± 0.4% and 67.2% ± 2.4%, respectively. All drugloaded PEG-PRL micelles exhibit a similar release behavior with a sustained release up to 72 hours. The PEG-PRL was shown to be nontoxic against MCF-7 and human umbilical vein endothelial cells up to a concentration of 100 μg/mL, displaying a good biocompatibility. Also, the docetaxel-loaded PEG-PRL micelles were more toxic than the free drug against MCF-7 human breast cancer cells -both dose and time dependent. Therefore, these high docetaxel-loaded micelles based on racemic hybrid polypeptides appear to be a novel promising nanomedicine for anticancer therapy.