Perylene Diimide Hexamer Based on Combination of Direct and Indirect Linkage Manners for Non-fullerene Organic Solar Cells

Perylene diimide (PDI) is one of the most intensively studied building blocks for the construction of non-fullerene acceptors (NFAs). In this contribution, based on combination of the direct and indirect linkage manners of PDI units at the bay position, a propeller-shaped PDI hexamer T-DPDI was designed and synthesized. The singly bonded PDI dimer DPDI and the benzene ring cored PDI trimer TPDI were synthesized for comparison. The photovoltaic performances of these three PDI derivatives were investigated using the commercially available PTB7-Th as electron donor. A best power conversion efficiency (PCE) of 6.58% was obtained for T-DPDI based organic solar cells (OSCs), which is higher than those of DPDI and TPDI based ones. The superior photovoltaic performance of T-DPDI can be ascribed to its stronger absorption and more favorable morphology. This study presents an interesting example of improving the photovoltaic performances of PDI based NFAs by hybridizing the direct and indirect linkage manners.

Nanostructured Organic/Hybrid Materials and Components in Miniaturized Optical and Chemical Sensors

In the last decade, biochemical sensors have brought a disruptive breakthrough in analytical chemistry and microbiology due the advent of technologically advanced systems conceived to respond to specific applications. From the design of a multitude of different detection modalities, several classes of sensor have been developed over the years. However, to date they have been hardly used in point-of-care or in-field applications, where cost and portability are of primary concern. In the present review we report on the use of nanostructured organic and hybrid compounds in optoelectronic, electrochemical and plasmonic components as constituting elements of miniaturized and easy-to-integrate biochemical sensors. We show how the targeted design, synthesis and nanostructuring of organic and hybrid materials have enabled enormous progress not only in terms of modulation and optimization of the sensor capabilities and performance when used as active materials, but also in the architecture of the detection schemes when used as structural/packing components. With a particular focus on optoelectronic, chemical and plasmonic components for sensing, we highlight that the new concept of having highly-integrated architectures through a system-engineering approach may enable the full expression of the potential of the sensing systems in real-setting applications in terms of fast-response, high sensitivity and multiplexity at low-cost and ease of portability.

Fusion of thienyl into the backbone of electron acceptor in organic photovoltaic heterojunctions: a comparative study of BTPT-4F and BTPTT-4F

The fusion of thiophene into a non-fullerene acceptor backbone causes significant suppression of the charge recombination rate at the donor/acceptor heterojunction interface.

Importance of Side-Chains on Molecular Characteristics of Interacting Organic Molecules

In this work, we have calculated several physical quantities related to two interacting semiconductor organic molecules to reveal the significance and the role of the side-chains. The molecular systems of our target are the geometry-optimized dimer systems: that consisting of two [6,6]-phenyl-C₆₁-butyric acid methyl ester molecules and that consisting of two peryline diimide-related molecules. The physical quantities shown in the present work are their relative molecular geometries, optimized energies, barycentric distances, angles between the two molecular planes, dipole moments, and electronic couplings. We have found that these physical quantities show quite different tendencies among the systems, which results from the absence/presence of the side-chains in these molecular species. It is emphasized that the presence of side-chains brings about the diversity of molecular characteristics in interacting molecules. This may point out the importance of side-chains in the various organic materials in general.