Tin oxide (SnO 2 ) is widely used in perovskite solar cells (PSCs) as an electron transport layer (ETL) material. However, its high surface trap density has already become a strong factor limiting PSC development. In this work, phosphoric acid is adopted to eliminate the SnO 2 surface dangling bonds to increase electron collection efficiency. The phosphorus mainly exists at the boundaries in the form of chained phosphate groups, bonding with which more than 47.9% of Sn dangling bonds are eliminated. The reduction of surface trap states depresses the electron transport barriers, thus the electron mobility increases about 3 times when the concentration of phosphoric acid is optimized with 7.4 atom % in the SnO 2 precursor. Furthermore, the stability of the perovskite layer deposited on the phosphate-passivated SnO 2 (P-SnO 2 ) ETL is gradually improved with an increase of the concentration. Due to the higher electron collection efficiency, the P-SnO 2 ETLs can dramatically promote the power conversion efficiency (PCE) of the PSCs. As a result, the champion PSC has a PCE of 21.02%. Therefore, it has been proved that this simple method is efficient to improve the quality of ETL for high-performance PSCs.

Compared with traditional chemotherapeutics, vascular disruption agents (VDAs) have the advantages of rapidly blocking the supply of nutrients and starving tumors to death. Although the VDAs are effective under certain scenarios, this treatment triggers angiogenesis in the later stage of therapy that frequently leads to tumor recurrence and treatment failure. Additionally, the nonspecific tumor targeting and considerable side effects also impede the clinical applications of VDAs. Here we develop a customized strategy that combines a VDA with an anti-angiogenic drug (AAD) using mesoporous silica nanoparticles (MSNs) coated with platelet membrane for the self-assembled tumor targeting accumulation. The tailor-made nanoparticles accumulate in tumor tissues through the targeted adhesion of platelet membrane surface to damaged vessel sites, resulting in significant vascular disruption and efficient anti-angiogenesis in animal models. This study demonstrates the promising potential of combining VDA and AAD in a single nanoplatform for tumor eradication.

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Conventional titanium oxide (TiO 2) as an electron transport layer (ETL) in hybrid organic-inorganic perovskite solar cells (PSCs) requires a sintering process at a high temperature to crystalize, which is not suitable for flexible PSCs and tandem solar cells with their low-temperatureprocessed bottom cell. Here, we introduce a low-temperature solution method to deposit a TiO 2 /tin oxide (SnO 2) bilayer towards an efficient ETL. From the systematic measurements of optical and electronic properties, we demonstrate that the TiO 2 /SnO 2 ETL has an enhanced charge extraction ability and a suppressed carrier recombination at the ETL/perovskite interface, both of which are beneficial to photo-generated carrier separation and transport. As a result, PSCs with TiO 2 /SnO 2 bilayer ETLs present higher photovoltaic performance of the baseline cells compared with their TiO 2 and SnO 2 single-layer ETL counterparts. The champion PSC has a power conversion efficiency (PCE) of 19.11% with an open-circuit voltage (V oc) of 1.15 V, a short-circuit current density (J sc) of 22.77 mA cm −2 , and a fill factor (FF) of 72.38%. Additionally, due to the suitable band alignment of the TiO 2 /SnO 2 ETL in the device, a high V oc of 1.18 V is achieved. It has been proven that the TiO 2 /SnO 2 bilayer is a promising alternative ETL for high efficiency PSCs.

The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/solr.202200175.

Electron-transport layer (ETL) that promotes charge carrier separation and electron extraction is a key component of perovskite solar cells (PSCs). Here, we report a simple approach for improving carrier collection efficiency of PSCs by the ZnO-modified ITO in a low-temperature solution process. With the inset of a ZnO layer between the ITO substrate and the SnO 2 ETL, the adverse energy band alignment can be eliminated and thus an Ohmic contact between the ITO and SnO 2 ETL can be expected. Additionally, the scanning electron microscope images show that the SnO 2 film deposited on the ZnO-modified ITO substrate has a lower surface roughness than those directly on the ITO, contributing to the formation of larger grain sizes and better crystalline properties of perovskite. On the basis of photoluminescence and impedance spectrum measurements, the addition of ZnO modification layer facilitates the efficient separation and transportation of photogenerated carriers from the perovskite absorber due to the improved contact resistance and electrical conductivity of ETL. Through such a simple approach, the PSC with the highest power conversion efficiency of 20.45% has been obtained. Our work highlights the importance of electrode/ ETL contact and paves the way for further optimizing the performances of PSCs.

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In recent years, ultrathin Ag films (UTAFs), which are attractive owing to its extremely low resistance, relatively high transparency, excellent mechanical flexibility, and mature mass production, have been reported as potential candidates to replace traditional indium tin oxide (ITO). To achieve a high-quality UTAF, a nucleation-inducing seed layer (NISL) is required to address the issue of irregular Ag islands growth. However, the structures of films so deposited are still far from being ideal and consist of rough surfaces with high densities of voids and grain boundaries when the film thickness is < ∼6 nm. Here, a hybrid structure composed of a gold (Au)/polyethyleneimine (PEI) bilayer is employed as a high-density NISL for the fabrication of an UTAF. Compared to the conventional single-layered PEI NISL that physisorbed on the substrate via the weak electrostatic attraction between the negatively charged substrate and the positively charged amine groups in PEI, our novel bilayered Au/PEI NISL exhibits a much higher density of nucleation sites due to the formation of strong coordinate covalent bonds between the Au atoms and amine groups. As a result, the percolation threshold thickness of the UTAF based on the Au/PEI bilayer can be reduced to as low as 3 nm. After capping with a high-refractive-index tantalum pentoxide (Ta 2 O 5 ) anti-reflection layer, the resultant Au/PEI/8 nm Ag/30 nm Ta 2 O 5 (APAT) electrode exhibits an excellent optoelectrical performance with a sheet resistance of 9.07 /sq and transmittance of 92.9% in the spectral range of 400-800 nm as well as outstanding long-term environmental and mechanical stabilities. The findings demonstrate a novel strategy for the development of high-performance UTAF-based transparent electrodes.