Selective Growth of Covalent Organic Framework Ultrathin Films on Hexagonal Boron Nitride

Abstract

Incorporating the intriguing covalent organic framework (COF) into devices and performing their advanced electronic nature are still challenging. Herein, we demonstrate the direct growth of 2D full-conjugated COF ultrathin films on dielectric hexagonal boron nitride (hBN) for the first time and study the carrier transporting characteristics of π-conjugated COF films. Under the optimized solvothermal conditions, few-layered COF-366 films with the covalent connection of tetra(p-aminophenyl)porphyrin and terephthaladehyde are selectively fabricated on mechanically exfoliated hBN flakes. COF-366 films on hBN substrate present red-shift absorption edge and decreased band gap compared to the bulk COF powders.The organic field-effect transistor device based on COF-366 ultrathin films demonstrates p-type current modulation with an On/Off ratio of 10 5 and mobility of 0.015 cm 2 V -1 s -1 . The present work represents a universal method for COF film growth on dielectric surface, and also provides important insight to the carrier transport of 2D π-conjugated system and potential applications of 2D COFs in electronics.

Photoactive and Conducting Covalent Organic Frameworks

“…COF-366 was grown as thin film in situ on boron nitride surfaces which were later used to construct an FET device. [32] Wang and co-workers reported an OFET device based on COF-366 ultrathin films featuring a p-type current modulation with an on/off ratio of 10 5 and mobility value of 0.015 cm 2 V −1 s −1…”

Covalent Organic Frameworks: Chemical Approaches to Designer Structures and Built‐In Functions

“…Immersion of substrates into the bulk reaction systems under solvothermal conditions enables the growth of thin films on graphene, hexagonal boron nitride (hBN), glass, polydopamine‐coated capillary, and HOPG . COF‐5, ZnPc‐PBBA‐COF, COF‐366, BDT‐COF, and DAB‐TFP‐COF have been prepared as thin films with thicknesses ranging from several nanometers to 7 μm on substrates.…”

Kovalente organische Gerüstverbindungen: chemische Ansätze für Designerstrukturen und integrierte Funktionen

“…Eintauchen von Substraten in Volumenreaktionssysteme unter Solvothermalbedingungen ermöglicht das Wachstum dünner Filme auf Graphen, hexagonalem Bornitrid (hBN), Glas, Polydopamin‐beschichteten Kapillaren und HOPG . COF‐5, ZnPc‐PBBA‐COF, COF‐366, BDT‐COF und DAB‐TFP‐COF sind als dünne Filme mit Dicken von mehreren nm bis 7 μm auf Substraten hergestellt worden.…”

“…[105] Ein Ansatz zur Lçsung dieses Problems ist das Steuern der Wasserdampfkonzentration, sodass die strukturelle Selbstheilung durch eine erhçhte Reversibilitätd er Reaktion gefçrdert wird, mit der Folge einer Entstehung einzelner SCOF-Schichten mit hoher Qualität. [111] Eintauchen von Substraten in Volumenreaktionssysteme unter Solvothermalbedingungen ermçglicht das Wachstum dünner Filme auf Graphen, [114,115] hexagonalem Bornitrid (hBN), [116] Glas, [117,118] Polydopamin-beschichteten Kapillaren [119] und HOPG. [120] COF-5, ZnPc-PBBA-COF,C OF-366, BDT-COF und DAB-TFP-COF sind als dünne Filme mit Dicken von mehreren nm bis 7 mmauf Substraten hergestellt worden.…”