Dynamic self-stabilization in the electronic and nanomechanical properties of an organic polymer semiconductor

Abstract

The field of organic electronics has profited from the discovery of new conjugated semiconducting polymers that have molecular backbones which exhibit resilience to conformational fluctuations, accompanied by charge carrier mobilities that routinely cross the 1 cm2/Vs benchmark. One such polymer is indacenodithiophene-co-benzothiadiazole. Previously understood to be lacking in microstructural order, we show here direct evidence of nanosized domains of high order in its thin films. We also demonstrate that its device-based high-performance electrical and thermoelectric properties are not intrinsic but undergo rapid stabilization following a burst of ambient air exposure. The polymer’s nanomechanical properties equilibrate on longer timescales owing to an orthogonal mechanism; the gradual sweating-out of residual low molecular weight solvent molecules from its surface. We snapshot the quasistatic temporal evolution of the electrical, thermoelectric and nanomechanical properties of this prototypical organic semiconductor and investigate the subtleties which play on competing timescales. Our study documents the untold and often overlooked story of a polymer device’s dynamic evolution toward stability.

Improving Carrier Mobility of Near-Amorphous Donor–Acceptor Conjugated Polymer Thin Films via Promoting Intensive and Continuous Polymer Aggregations

“…However, recent results obtained by high-resolution transmission electron microscopy and atomic force microscopy (AFM) have challenged this perception. 25,26 Specifically, the IDTBT film exhibits nanoscale order between 10 and 15 nm by mapping the skeleton (001) spacing reflectance in local space. The film contains a large number of nanocrystals.…”

“…Both the corresponding (200) and (010) reflections in the two-dimensional grazing-incidence wide-angle X-ray scattering (2D GIWAXS) detections have indicated the broad arc signals of the film, which illustrates the formation of tiny-scaled IDTBT crystallites with wide orientation distribution. , IDTBT is often expected to present comprehensive local molecular order because of the consistency of the π-conjugated planar orientation between the amorphous regions and crystalline regions. However, recent results obtained by high-resolution transmission electron microscopy and atomic force microscopy (AFM) have challenged this perception. , Specifically, the IDTBT film exhibits nanoscale order between 10 and 15 nm by mapping the skeleton (001) spacing reflectance in local space. The film contains a large number of nanocrystals.…”

Dynamic Covalent Bond Network-Based Carbon Nanocomposite for a Self-Healing Tactile Sensor

“…Self-healing materials have attracted attention in many applications because they enable autonomous control of the life of a material due to their ability to recover damage under certain conditions. Among them, polymer self-healing materials have more applications because they can be restored to their original structures under mild conditions than shape memory alloys. − Self-healing polymers mainly have reversible chemical bonds such as disulfide, diels–alder, trans-esterification, and hydrogen bonds in their chain structure. Thus, they can work according to the presence or absence of specific external stimuli. − Many studies have been conducted on self-healing polymers.…”

Fabrication and Characterization of Self-Healable Polydisulfide Network-Based Composites

“…Recently, researches have been actively conducted on the synthesis of dynamic polymer structures that form polymer networks by using various reversible chemical covalent bonds as cross-linking between chains. − There are several types of reversible covalent bonds designed to date, such as CN, C–C, CC, C–O, S–S, Se–Se, B–O, and Si–O, and more bonds are currently being found. − The various proposed reversible covalent bonds break existing bonds with external stimuli (e.g., changes in physical contact or heat, ultraviolet, or pH), and bonds are created. − The characteristics allow for the structural dynamics of polymer networks generated by cross-linking with reversible covalent bonds. − Thus, reversible covalent-based polymer structures are used in applications requiring dynamics, such as cell adhesives, cell regeneration, drug delivery, pressure sensor devices, and coating materials. − In addition, a combination of a cross-linking agent and a dynamic covalent bond can be applied as a shape memory material that under specific conditions is capable of returning to its original shape. − However, until now, research on the material has focused on the development of a polymer chain structure capable of reversible covalent bonding in a form. In addition, research on forming composite materials with other materials and applying them to application fields is still insufficient.…”