Unravelling the Correlation between Charge Mobility and Cocrystallization in Rod–Rod Block Copolymers for High‐Performance Field‐Effect Transistors

Abstract

Cocrystallization involving two or more components aggregating into cocrystals allows the preparation of materials with markedly improved charge mobility. This approach however, is little explored in all-conjugated block copolymers (BCPs). Herein, we report the first investigation into the correlation between cocrystals and charge mobility in a series of new all-conjugated BCPs: poly(3-butylthiophene)-b-poly(3-hexylselenophene) (P3BT-b-P3HS) for high-performance field-effect transistors. These rationally synthesized rod-rod BCPs self-assemble into cocrystals with high charge mobilities. Upon one-step thermal annealing, their charge mobilities decrease slightly despite their increased crystallinities. After two-step thermal annealing, P3BT-b-P3HS (P3BT/P3HS=2:1) and (1:1) cocrystals disappear and phase separation occurs, leading to greatly decreased charge mobilities. In contrast, P3BT-b-P3HS (1:2) retains its cocrystalline structure and its charge mobility.

Large-Scale Alignment of Polymer Semiconductor Nanowires for Efficient Charge Transport via Controlled Evaporation of Confined Fluids

“…Over the past decade, conjugated polymers have attracted great attention in diverse research fields such as organic field-effect transistors (OFETs), organic light-emitting diodes, and organic photovoltaic cells as well as chemical sensors and biosensors, due to the benefits arising from low temperature, solution-based processability. , However, polymer semiconductors exhibit relatively inferior charge transport properties to their inorganic counterparts, owing to low crystallinity (i.e., intra- and interchain interactions), high grain boundary density, and poor orientation of crystal grains, resulting in low device performance. − Typically, charge transport in these polymers takes place preferentially along the direction of p-orbital overlap, which can occur within and/or between individual polymer chains . Therefore, it is of great importance to organize polymer chains into a desired configuration such as a well-ordered one-dimensional (1D) nanostructure and further, to align these 1D nanostructures in the desired direction.…”

Growth direction dependent separate-channel charge transport in the organic weak charge-transfer co-crystal of anthracene–DTTCNQ

“…[26][27][28][29][30] Compared with individual donors or individual acceptors, the formation of organic co-crystals based on donors and acceptors creates many possibilities (such as binary, 26 ternary, 31 or multinary 32,33 co-crystals) for semiconductors as well as improves the structural stability. 34,35 To date, different charge transport properties, including pure hole transport, [36][37][38][39] pure electron transport, 38,[40][41][42][43][44][45] and ambipolar transport properties, 38,42,[46][47][48][49][50][51][52][53][54][55] have been reported by different research groups depending on their technologies of molecular structure explorations and device fabrications. It is necessary to tune the semiconducting properties; especially the balanced control of hole and electron transport can drive us to predict, design, and fabricate organic semiconducting co-crystals for applications.…”

Molecular cocrystal odyssey to unconventional electronics and photonics

“…[2,3]. Among the large crystal family, organic cocrystal is a special type of single crystal material crystallized from two or more different components [4], such as polymer [5] or small molecule [6,7]. Polymers are chemically produced batch-to-batch with un-controllable molecular weight and dispersity, generally show weak p-p face-on/edge-on interaction and low crystallinity, and thus their cocrystals are limited presented in literature.…”