Self-Aligned Bilayers for Flexible Free-Standing Organic Field-Effect Transistors

Improving Photosensitivity and Transparency in Organic Phototransistor with Blending Insulating Polymers

Organic phototransistors exhibit great promise for use in a wide range of technological applications due to their flexibility, low cost, and low-temperature processability. However, their low transparency due to visible light absorption has hindered their adoption in next-generation transparent electronics. For this reason, the present study sought to develop a highly sensitive organic phototransistor with greater transparency and significantly higher light sensitivity in the visible and UVA regions without deterioration in its electrical properties. An organic blended thin-film transistor (TFT) fabricated from the blend of an organic semiconductor and an insulating polymer demonstrated improved electrical properties in the dark and a higher current under light irradiation even though its transmittance was higher. The device exhibited a transmittance of 87.28% and a photosensitivity of 7049.96 in the visible light region that were 4.37% and 980 times higher than those of the single-semiconductor-based device. The carrier mobility of the device blended with the insulating polymer was improved and greatly amplified under light irradiation. It is believed that the insulating polymer facilitated the crystallization of the organic semiconductor, thus promoting the flow of photogenerated excitons and improving the photocurrent. Overall, the proposed TFT offers excellent low-temperature processability and has the potential to be employed in a range of transparent electronic applications.

Non-Covalent Interaction on the Self-Healing of Mechanical Properties in Supramolecular Polymers

Supramolecular polymers are widely utilized and applied in self-assembly or self-healing materials, which can be repaired when damaged. Normally, the healing process is classified into two types, including extrinsic and intrinsic self-healable materials. Therefore, the aim of this work is to review the intrinsic self-healing strategy based on supramolecular interaction or non-covalent interaction and molecular recognition to obtain the improvement of mechanical properties. In this review, we introduce the main background of non-covalent interaction, which consists of the metal–ligand coordination, hydrogen bonding, π–π interaction, electrostatic interaction, dipole–dipole interaction, and host–guest interactions, respectively. From the perspective of mechanical properties, these interactions act as transient crosslinking points to both prevent and repair the broken polymer chains. For material utilization in terms of self-healing products, this knowledge can be applied and developed to increase the lifetime of the products, causing rapid healing and reducing accidents and maintenance costs. Therefore, the self-healing materials using supramolecular polymers or non-covalent interaction provides a novel strategy to enhance the mechanical properties of materials causing the extended cycling lifetime of products before replacement with a new one.