High-mobility semiconducting polymers with different spin ground states

Abstract

Organic semiconductors with high-spin ground states are fascinating because they could enable fundamental understanding on spin-related phenomenon in light element and provide opportunities for organic magnetic and quantum materials. Although high-spin ground states have been observed in some quinoidal type small molecules or doped organic semiconductors, semiconducting polymers with high-spin at its neutral ground state are rarely reported because of the less of clear design strategy. Here we propose a molecular design strategy to obtain high-mobility semiconducting polymers with different spin ground states. We show that polymer building blocks with small singlet-triplet energy gap (ΔES−T) could enable small ΔES−T gap and increase the diradical character in copolymers. We first demonstrate that the spin density and solid-state interchain interactions in the high-spin polymers are crucial for their ground states. Polymers with a triplet ground state (S = 1) could exhibit doublet (S = 1/2) behavior due to the solid-state interchain spin-spin interactions. Besides, these polymers showed outstanding charge transport properties with high hole/electron mobilities and can be both n- and p-doped with superior conductivities. Our results demonstrate a rational design approach to high-mobility semiconducting polymers with different spin ground states.

Molecular mechanism of rigidity- and planarity-promoted, state-dependent doping of conjugated ladder-type molecules

“…[22][23][24][25][26][27] Over the past decade, doping strategies using organic compounds have emerged as an alternative approach for addressing these issues. [28][29][30] In these cases, neutral organic molecular species serve as either electron-accepting or -donating dopants. [22][23][24][25][26] In addition, this class of strategies offers the advantages of processing versatility and structural flexibility for tailored properties.…”