Hydrophenazine-linked two-dimensional ladder-type crystalline fused aromatic network with high charge transport

Abstract

•A ladder-type hydrophenazine-linked 2D fused aromatic network (HP-FAN) was realized •The HP-FAN has an inherent semiconducting band gap along with a parallel flat band •The HP-FAN has high intrinsic electrical conductivity without doping •The HP-FAN exhibits a remarkable performance in electronic devices with high mobility Since the advent of graphene, the development of crystalline two-dimensional (2D) organic materials with semiconducting features has been extensively explored for their potential optoelectronic applications. Despite extensive progress in this field, it is still challenging to realize laterally extended organic materials with high electrical transport properties. Here, we report a 2D ladder-type fused aromatic network (FAN) in which backbones are composed of hydrophenazine (HP) linkage (designated HP-FAN). Consequently, its 2D extended delocalization of π-molecular orbitals imparts a semiconducting band gap and facilitates fast intra-chain charge transport. The as-prepared HP-FAN exhibits semiconducting features with calculated and experimental band gaps of approximately 1.44 and 1.54 eV, respectively, with an unusual flat band. The HP-FAN thin flakes, isolated by polydimethylsiloxane stamping, exhibit remarkable performance in a p-type field-effect transistor (FET) and a Hall effect device. Given its laterally extended ladder-type π-conjugated structure, the HP-FAN has extensive potential for applications in thin-film optoelectronic devices. Since the advent of graphene, the development of crystalline two-dimensional (2D) organic materials with semiconducting features has been extensively explored for their potential optoelectronic applications. Despite extensive progress in this field, it is still challenging to realize laterally extended organic materials with high electrical transport properties. Here, we report a 2D ladder-type fused aromatic network (FAN) in which backbones are composed of hydrophenazine (HP) linkage (designated HP-FAN). Consequently, its 2D extended delocalization of π-molecular orbitals imparts a semiconducting band gap and facilitates fast intra-chain charge transport. The as-prepared HP-FAN exhibits semiconducting features with calculated and experimental band gaps of approximately 1.44 and 1.54 eV, respectively, with an unusual flat band. The HP-FAN thin flakes, isolated by polydimethylsiloxane stamping, exhibit remarkable performance in a p-type field-effect transistor (FET) and a Hall effect device. Given its laterally extended ladder-type π-conjugated structure, the HP-FAN has extensive potential for applications in thin-film optoelectronic devices.