Effects of the Donor Unit on the Formation of Hybrid Layers of Donor-Acceptor Copolymers with Silver Nanoparticles.

Donor-acceptor (D-A) copolymers containing perylene-3,4,9,10-tetracarboxydiimide (PDI) electron-acceptor (A) units belonging to n-type semiconductors are of interest due to their many potential applications in photonics, particularly for electron-transporting layers in all-polymeric or perovskite solar cells. Combining D-A copolymers and silver nanoparticles (Ag-NPs) can further improve material properties and device performances. Hybrid layers of D-A copolymers containing PDI units and different electron-donor (D) units (9-(2-ethylhexyl)carbazole or 9,9-dioctylfluorene) with Ag-NPs were prepared electrochemically during the reduction of pristine copolymer layers.

Formamidinium Lead Iodide Perovskite Thin Films Formed by Two-Step Sequential Method: Solvent-Morphology Relationship.

Thin films made of formamidinium lead iodide (FAPbI) perovskites prepared by a two-step sequential deposition method using various solvents for formamidinium iodide (FAI) - isopropanol, -butanol and -butanol, were studied with the aim of finding a correlation between morphology and solvent properties to improve film quality. They were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) and their photophysical properties were studied by means of absorption and photoluminescence (PL) spectroscopies. XRD patterns, absorption and PL spectra proved α-phase formation for all selected solvents.

Synthesis of MAPbBr -Polymer Composite Films by Photolysis of DMF: Toward Transparent and Flexible Optical Physical Unclonable Functions (PUFs) with Hierarchical Multilevel Complexity.

Physical entities with inherent randomness have been investigated as anti-counterfeiting labels based on physical unclonable functions (PUFs). Herein, a transparent and flexible optical PUF label associated with multilevel complexity is demonstrated by taking advantage of the optical properties of hierarchical morphologies of the composite film composed of metal halide perovskite nanoparticles (MAPbBr NPs) and the intrinsic spinodal-decomposition-like phase separation of polymer blend (PMMA/PS blend). Due to the combinatorial effects of the photolysis synthesis of MAPbBr and the thermodynamic instability of the PMMA/PS blend, randomized patterns emerge at two-level scales.

Hybrid Layers of Donor-Acceptor Copolymers with Homogenous Silver Nanoparticle Coverage for Photonic Applications.

Hybrid layers of donor-acceptor (D-A) copolymers containing -dialkylperylene-3,4,9,10-tetracarboxydiimide electron-acceptor units covered with silver nanoparticles (Ag-NPs) were prepared by electrochemical doping of pristine layers during reduction processes. In situ optical absorption spectra of the layers were recorded during the formation of Ag-NP coverage. The hybrid layers were characterized by absorption spectroscopy, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and energy dispersive X-ray spectroscopy (EDX).

Eutectic friction transfer lithography: a facile solid-state route for highly crystalline semiconducting polymers.

Herein, we report a solid-state lithography technique utilizing eutectic friction transfer lithography (EFTL). The EFTL technique employs eutectic pellets made of semiconducting polymers and volatile organic solid matrices. Using frictional heating and eutectic melting, various semiconducting polymer crystals were formed by a simple rubbing process under mild conditions.

Self-defect-passivation by Br-enrichment in FA-doped CsFAPbBr quantum dots: towards high-performance quantum dot light-emitting diodes.

Halide vacancy defect is one of the major origins of non-radiative recombination in the lead halide perovskite light emitting devices (LEDs). Hence the defect passivation is highly demanded for the high-performance perovskite LEDs. Here, we demonstrated that FA doping led to the enrichment of Br in CsFAPbBr QDs.

Perovskite Nanoparticle Composite Films by Size Exclusion Lithography.

Perovskite nanoparticle composite films with capability of high-resolution patterning (≥2 µm) and excellent resistance to various aqueous and organic solvents are prepared by in situ photosynthesis of acrylate polymers and formamidinium lead halide (FAPbX ) nanoparticles. Both positive- and negative-tone patterns of FAPbX nanoparticles are created by controlling the size exclusive flow of nanoparticles in polymer networks. The position of nanoparticles is spatially controlled in both lateral and vertical directions.