Enhancing the Carrier Transport in Monolayer MoS2 through Interlayer Coupling with 2D Covalent Organic Frameworks

• Published in: Advanced materials (Weinheim) 2024-01, Vol.36 (1), p.e2305882-n/a
• Main Authors: Wang, Can, Cusin, Luca, Ma, Chun, Unsal, Elif, Wang, Hanlin, Consolaro, Valentina Girelli, Montes‐García, Verónica, Han, Bin, Vitale, Stefania, Dianat, Arezoo, Croy, Alexander, Zhang, Haiming, Gutierrez, Rafael, Cuniberti, Gianaurelio, Liu, Zhaoyang, Chi, Lifeng, Ciesielski, Artur, Samorì, Paolo
• Format: Article
• Language: English
• Subjects: 2D covalent organic frameworks; Carrier transport; Charge transport; Chemical Sciences; Coupling; Design optimization; Digital electronics; Electron transfer; Electronics; Heterostructures; interface engineering; Interlayers; Lattice vibration; Molybdenum disulfide; Monolayers; Quantum computing; Room temperature; Synergistic effect; Thermal stability; Transition metal compounds; transition metal dichalcogenides; Transport properties; Two dimensional materials; van der Waals heterostructures
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202305882

The coupling of different 2D materials (2DMs) to form van der Waals heterostructures (vdWHs) is a powerful strategy for adjusting the electronic properties of 2D semiconductors, for applications in opto‐electronics and quantum computing. 2D molybdenum disulfide (MoS2) represents an archetypical semiconducting, monolayer thick versatile platform for the generation of hybrid vdWH with tunable charge transport characteristics through its interfacing with molecules and assemblies thereof. However, the physisorption of (macro)molecules on 2D MoS2 yields hybrids possessing a limited thermal stability, thereby jeopardizing their technological applications. Herein, the rational design and optimized synthesis of 2D covalent organic frameworks (2D‐COFs) for the generation of MoS2/2D‐COF vdWHs exhibiting strong interlayer coupling effects are reported. The high crystallinity of the 2D‐COF films makes it possible to engineer an ultrastable periodic doping effect on MoS2, boosting devices’ field‐effect mobility at room temperature. Such a performance increase can be attributed to the synergistic effect of the efficient interfacial electron transfer process and the pronounced suppression of MoS2’s lattice vibration. This proof‐of‐concept work validates an unprecedented approach for the efficient modulation of the electronic properties of 2D transition metal dichalcogenides toward high‐performance (opto)electronics for CMOS digital circuits. The interfacing of monolayer MoS2 with 2DCOF films determines a major enhancement in the charge transport through the 2D semiconductor. Electron doping intensity is amplified by the superlattice's long‐range order, while the lattice vibration is suppressed by the high mechanical stiffness yielding a confinement effect. The MoS2 /2D‐COF heterostructures represent a novel strategy to develop high‐performance 2D electronics.