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

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 ₂O. The morphology and structure characterization reveal that this film is piled up by nanosheets of 2D lattice of [Cu ₃(C ₆S 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 ²V ⁻¹s ⁻¹ for holes and 116 cm ²V ⁻¹s ⁻¹ for electrons) under field-effect modulation.

Abstract

Conjugated 2D materials are able to marry the properties of transparency and conductivity for implementation in a wide range of devices. Here, Huang and et al. adopt this design principal in synthesizing a copper bis(dithiolene) coordination polymer which exhibits remarkable electronic performances.