Dual Optimization of Bulk and Interface via the Synergistic Effect of Ligand Anchoring and Hole Transport Dopant Enables 23.28% Efficiency Inverted Perovskite Solar Cells.

The crystalline morphology of perovskite film plays a key role in determining the stability and performance of perovskite solar cells (PSCs). In addition, the work function and conductivity of hole transport layer (HTL) have a great influence on the effciency of PSCs. Here, we develop a synergistic doping strategy to fabricate high-performance inverted PSCs, doping a functional nanographene (C78-AHM) into the poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine (PTAA) HTL, thus forming an HTL with higher conductivity, lower roughness, and frontier energy levels matching the perovskite absorber work function. On this basis, thiosemicarbazide (TSC) was doped into the precursor solution of perovskite as the grain and interface modifier to further improve the crystalline morphology of perovskite film. Compared with the current single passivation method, this codoping strategy can simultaneously reduce the surface and bulk defects of perovskite film and reduce the interface energy barrier. Eventually, high-quality TSC-doped perovskite films based on C78-AHM-doped PTAA HTL are obtained with over 2 µm sized grains, pinhole-free, and improved crystallinity. As a result, this synergistic doping strategy increases the efficiency of the device from 20.27% to 23.28%. Furthermore, the environmental and thermal stabilities of the devices are significantly improved. Therefore, this work provides a simple way for the preparation of other efficient optoelectronic devices.

Graphene nanoribbon-based supramolecular ensembles with dual-receptor targeting function for targeted photothermal tumor therapy.

Triple negative breast cancer (TNBC) is one of the most malignant subtypes of breast cancer. Here, we report the construction of graphene nanoribbon (GNR)-based supramolecular ensembles with dual-receptor (mannose and αvß3 integrin receptors) targeting function, denoted as GNR-Man/PRGD, for targeted photothermal treatment (PTT) of TNBC. The GNR-Man/PRGD ensembles were constructed through the solution-based self-assembly of mannose-grafted GNRs (GNR-Man) with a pyrene-tagged αvß3 integrin ligand (PRGD). Enhanced PTT efficacies were achieved both in vitro and in vivo compared to that of the non-targeting equivalents. Tumor-bearing live mice were administered (tail vein) with GNR-Man/PRGD and then each mice group was subjected to PTT. Remarkably, GNR-Man/PRGD induced complete ablation of the solid tumors, and no tumor regrowth was observed over a period of 15 days. This study demonstrates a new and promising platform for the development of photothermal nanomaterials for targeted tumor therapy.

Degradation of Structurally Defined Graphene Nanoribbons by Myeloperoxidase and the Photo-Fenton Reaction.

As an emerging member of the graphene family, structurally defined graphene nanoribbons (GNRs) have shown promising applications in various fields. The evaluation of the degradability of GNRs is particularly important for assessing the persistence level and risk of these materials in living organisms and the environment. However, there is a void in the study of the degradation of GNRs. Here, we report the degradation behavior of GNRs in the presence of human myeloperoxidase (hMPO) or treated with the photo-Fenton (PF) reaction. With the assistance of potassium hydroxide or imidazole, which facilitates the dispersion of GNRs in the aqueous solution, GNRs underwent only partial degradation after 25-hour incubation with hMPO, while, the PF reaction degraded GNRs almost completely after 120 hours. These results indicate that structurally precise GNRs can be efficiently degraded under suitable conditions, providing more opportunities for future applications in different fields.

Water-Insensitive Synthesis of Poly-ß-Peptides with Defined Architecture.

Biocompatible and proteolysis-resistant poly-ß-peptides have broad applications and are dominantly synthesized via the harsh and water-sensitive ring-opening polymerization of ß-lactams in a glovebox or using a Schlenk line, catalyzed by the strong base LiN(SiMe3 )2 . We have developed a controllable and water-insensitive ring-opening polymerization of ß-amino acid N-thiocarboxyanhydrides (ß-NTAs) that can be operated in open vessels to prepare poly-ß-peptides in high yields, with diverse functional groups, variable chain length, narrow dispersity and defined architecture. These merits imply wide applications of ß-NTA polymerization and resulting poly-ß-peptides, which is validated by the finding of a HDP-mimicking poly-ß-peptide with potent antimicrobial activities. The living ß-NTA polymerization enables the controllable synthesis of random, block copolymers and easy tuning of both terminal groups of polypeptides, which facilitated the unravelling of the antibacterial mechanism using the fluorophore-labelled poly-ß-peptide.

Naphthodifuran-based zigzag-type polycyclic arene with conjugated side chains for efficient photovoltaics.

Ladder-type conjugated structures with rigid and coplanar molecular frameworks feature longer effective conjugation, affirmative optoelectronic properties and strong intermolecular π-π interactions, which are ideal characteristics for organic photovoltaics. Here, a new "zigzag" angular-fused naphthodifuran (zNDF) based on alkoxyphenyl side chains was designed and synthesized. The distannylated zNDF building block was copolymerized with 4,7-di(5-bromothiophen-2-yl)-5,6-dioctyloxybenzo[c][1,2,5]thiadiazole and 5,8-bis(5-bromothiophen-2-yl)-2,3-bis(4-(2-ethylhexyloxy)-3-fluorophenyl)-6,7-difloroquinoxaline (Br-BT and Br-ffQx) acceptor units by Stille cross coupling reaction to form two new medium bandgap donor-acceptor polymers PzNDFP-BT and PzNDFP-ffQx, respectively. The photovoltaic properties of the copolymers blended with [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as an electron acceptor were investigated. A 6.9% efficiency was achieved from the single device based on the PzNDFP-BT : PC71BM (1 : 1.5, w/w) blend film with a 0.25% 1,8-diiodooctane (DIO) additive, which is among the highest efficiency for zNDF-based polymer solar cells.