Intrinsically distinct hole and electron transport in conjugated polymers controlled by intra and intermolecular interactions

Abstract

It is still a matter of controversy whether the relative difference in hole and electron transport in solution-processed organic semiconductors is either due to intrinsic properties linked to chemical and solid-state structure or to extrinsic factors, as device architecture. We here isolate the intrinsic factors affecting either electron or hole transport within the same film microstructure of a model copolymer semiconductor. Relatively, holes predominantly bleach inter-chain interactions with H-type electronic coupling character, while electrons’ relaxation more strongly involves intra-chain interactions with J-type character. Holes and electrons mobility correlates with the presence of a charge transfer state, while their ratio is a function of the relative content of intra- and inter-molecular interactions. Such fundamental observation, revealing the specific role of the ground-state intra- and inter-molecular coupling in selectively assisting charge transport, allows predicting a more favorable hole or electron transport already from screening the polymer film ground state optical properties.

Understanding Charge Transport in High‐Mobility p‐Doped Multicomponent Blend Organic Transistors

“…We call this method charge modulation microscopy (CMM). [30,[38][39][40] Besides the advantage related to EA, the higher resolution provides the capability of investigating the eventual presence of a different spatial distribution of optical transitions deriving from charge relaxed on the polymer and on the small molecule. We therefore employed CMM to obtain a map of charge-induced transitions along the channel of the FETs.…”

Effect of Electrical Stimulation Conditions on Neural Stem Cells Differentiation on Cross-Linked PEDOT:PSS Films

“…Among the electroconductive materials available to produce such platforms, the most used are metals and organic materials, namely graphene, and conjugated polymers. Conjugated polymers present numerous advantages toward neural tissue engineering applications, namely: (1) they can be processed into any desired 3D-shape (Garrudo et al, 2019a , b ; Kayser and Lipomi, 2019 ); (2) can be easily functionalized allowing the tailoring of their mechanical, chemical, and electrical properties; (3) can exhibit high electroconductivity values, approaching those of metals; and (4) combine ionic and electronic conductivity, improving the “quality” of the interfaces with biological tissues (Rivnay et al, 2014 ; Inal et al, 2018 ; Goel et al, 2019 ; Pace et al, 2019 ). While electronic conductivity promotes higher current flow across the material, ion conductivity may prove to be essential to interface with tissues, as electrical signals in the human body are predominantly associated to ion currents.…”

Regulating the Aggregation of Unfused Non‐Fullerene Acceptors via Molecular Engineering towards Efficient Polymer Solar Cells

“…Over the past few years, molecular design for high-performance UF-NFAs mainly focused on planarizing molecular backbone through non-covalent conformational locking, which has been proved as an effective strategy for efficient charge transport. [22][23][24][25][26][27][28][29] However, the correlation between device performance and the bulk-heterojunction active layer morphology in terms of the molecular conformations [26,27] and molecular packing patterns, [30][31][32][33][34][35][36][37][38] still remains unclear in the field of UF-NFAs. As revealed by our recent work on crystallographic analysis of highly efficient Y6 and CH1007 F-NFAs, [10] π-core interaction plays a crucial role in regulating the molecular geometry and triggering unique self-assembly that benefit photovoltaic performance.…”