Gabbett Cian, Kelly Adam G, Coleman Emmet, Doolan Luke, Carey Tian, Synnatschke Kevin, Liu Shixin, Dawson Anthony, O'Suilleabhain Domhnall, Munuera Jose, Caffrey Eoin, Boland John B, Sofer Zdeněk, Ghosh Goutam, Kinge Sachin, Siebbeles Laurens D A, Yadav Neelam, Vij Jagdish K, Aslam Muhammad Awais, Matkovic Aleksandar, Coleman Jonathan N
School of Physics, CRANN & AMBER Research Centres, Trinity College Dublin, Dublin 2, Ireland.
i3N/CENIMAT, Faculty of Science and Technology, Universidade NOVA de Lisboa, Campus de Caparica, 2829-516, Caparica, Portugal.
Nat Commun. 2024 May 28;15(1):4517. doi: 10.1038/s41467-024-48614-5.
Networks of nanowires, nanotubes, and nanosheets are important for many applications in printed electronics. However, the network conductivity and mobility are usually limited by the resistance between the particles, often referred to as the junction resistance. Minimising the junction resistance has proven to be challenging, partly because it is difficult to measure. Here, we develop a simple model for electrical conduction in networks of 1D or 2D nanomaterials that allows us to extract junction and nanoparticle resistances from particle-size-dependent DC network resistivity data. We find junction resistances in porous networks to scale with nanoparticle resistivity and vary from 5 Ω for silver nanosheets to 24 GΩ for WS nanosheets. Moreover, our model allows junction and nanoparticle resistances to be obtained simultaneously from AC impedance spectra of semiconducting nanosheet networks. Through our model, we use the impedance data to directly link the high mobility of aligned networks of electrochemically exfoliated MoS nanosheets (≈ 7 cm V s) to low junction resistances of ∼2.3 MΩ. Temperature-dependent impedance measurements also allow us to comprehensively investigate transport mechanisms within the network and quantitatively differentiate intra-nanosheet phonon-limited bandlike transport from inter-nanosheet hopping.
纳米线、纳米管和纳米片网络对于印刷电子学中的许多应用都很重要。然而，网络的导电性和迁移率通常受到颗粒之间电阻的限制，这种电阻通常被称为结电阻。事实证明，最小化结电阻具有挑战性，部分原因是难以测量。在这里，我们为一维或二维纳米材料网络中的导电现象开发了一个简单模型，该模型使我们能够从与颗粒尺寸相关的直流网络电阻率数据中提取结电阻和纳米颗粒电阻。我们发现多孔网络中的结电阻与纳米颗粒电阻率成比例，范围从银纳米片的5Ω到WS纳米片的24GΩ不等。此外，我们的模型允许从半导体纳米片网络的交流阻抗谱中同时获得结电阻和纳米颗粒电阻。通过我们的模型，我们利用阻抗数据直接将电化学剥离的MoS纳米片对齐网络的高迁移率（≈7cm² V⁻¹ s⁻¹）与约2.3MΩ的低结电阻联系起来。与温度相关的阻抗测量还使我们能够全面研究网络内的传输机制，并定量区分纳米片内声子限制的带状传输和纳米片间的跳跃传输。
