A two-dimensional π–d conjugated coordination polymer with extremely high electrical conductivity and ambipolar transport behaviour

TLDR

Studies on organic two‑dimensional materials with special optoelectronic properties are attracting great research interest, yet 2D organic systems with promising electrical transport properties remain rare. A highly crystalline thin film of the copper coordination polymer Cu‑BHT was prepared via a liquid–liquid interface reaction between BHT/dichloromethane and copper(II) nitrate/H₂O, yielding nanosheet‑piled 2D lattices of [Cu₃(C₆S₆)]ⁿ confirmed by morphology, structure, and quantum simulation. Four‑probe measurements show that the room‑temperature conductivity reaches 1,580 S cm⁻¹, the highest reported for coordination polymers, and the material exhibits ambipolar charge transport with electron and hole mobilities of 116 cm² V⁻¹ s⁻¹ and 99 cm² V⁻¹ s⁻¹, respectively.

Abstract

Abstract Currently, studies on organic two-dimensional (2D) materials with special optic-electronic properties are attracting great research interest. However, 2D organic systems possessing promising electrical transport properties are still rare. Here a highly crystalline thin film of a copper coordination polymer, Cu-BHT (BHT=benzenehexathiol), is prepared via a liquid–liquid interface reaction between BHT/dichloromethane and copper(II) nitrate/H 2 O. The morphology and structure characterization reveal that this film is piled up by nanosheets of 2D lattice of [Cu 3 (C 6 S 6 )] n , which is further verified by quantum simulation. Four-probe measurements show that the room temperature conductivity of this material can reach up to 1,580 S cm −1 , which is the highest value ever reported for coordination polymers. Meanwhile, it displays ambipolar charge transport behaviour and extremely high electron and hole mobilities (99 cm 2 V −1 s −1 for holes and 116 cm 2 V −1 s −1 for electrons) under field-effect modulation.