Electronic properties and circuit applications of networks of electrochemically exfoliated 2D nanosheets
Tian Carey, Kevin Synnatschke, Goutam Ghosh, Luca Anzi, Eoin Caffrey, Emmet Coleman, Changpeng Lin, Anthony Dawson, Shixin Liu, Rebekah A. Wells, Mark McCrystall, Jan Plutnar, Iva Plutnarová, Joseph Neilson, Nicola Marzari, Laurens D. A. Siebbeles, Roman Sordan, Zdeněk Sofer, Jonathan N. Coleman
Abstract
Abstract High aspect-ratio 2D materials are promising for solution-processed electronics, yet the factors controlling exfoliation remain unclear and relatively few solution-processed networks have been electrically characterized. Here we combine theory and experiment to show that electrochemical exfoliation of layered crystals with sufficient stiffness-anisotropy (in-plane/out-of-plane Young’s modulus ratio >1.7) yields high aspect-ratio nanosheets with intrinsic mobilities μ NS = 20–75 cm²V⁻¹s⁻¹ across transition metal dichalcogenides and related alloys. Impedance spectroscopy indicates that solution-deposited networks can achieve junction-to-nanosheet resistance ratios (R J /R NS ) as low as ~3, supporting theoretical predictions that μ NS / μ Net = R J /R NS + 1 and suggesting that further reductions in R J will increase μ Net toward the nanosheet limit ( μ NS ). These networks display n-type, p-type, and ambipolar behaviour, with on/off ratios up to 10⁵ and mobilities μ Net = 13 cm²V⁻¹s⁻¹. Here, we show that such high-performing 2D materials enable functional solution-processed circuits, including inverters, buffers, a 4-bit digital-to-analog converter, and a circuit capable of encoding and decoding 7-bit ASCII messages.