M.C. Hersam
Northwestern University,
United States
Keywords: printable, flexible, electronics, photovoltaics, batteries, heterojunctions
Summary:
Layered two-dimensional nanomaterials interact primarily via van der Waals bonding, which has created new opportunities for heterostructures that are not constrained by epitaxial growth [1]. In order to efficiently explore the vast phase space for van der Waals heterostructures, our laboratory employs solution-based additive assembly [2]. In particular, constituent two-dimensional nanomaterials (e.g., graphene, boron nitride, transition metal dichalcogenides, black phosphorus, and indium selenide) are isolated in solution [3], and then deposited into thin films with scalable additive manufacturing methods (e.g., aerosol, inkjet, gravure, and screen printing) [4]. By achieving high levels of nanomaterial monodispersity and printing fidelity [5], a variety of electronic, electrochemical, and photonic applications can be enhanced including digital logic circuits [6], lithium-ion batteries [7], and photodetectors [8]. Furthermore, by integrating multiple nanomaterial inks into heterostructures, unprecedented device function is realized including anti-ambipolar transistors [9], ultrathin photovoltaics [10], gate-tunable memristors [11], and neuromorphic memtransistors [12]. In addition to technological implications for electronic and energy technologies, this talk will explore several fundamental issues including band alignment, doping, trap states, and charge/energy transfer across van der Waals heterointerfaces [13,14]. [1] D. Jariwala, et al., Nature Materials, 16, 170 (2017). [2] J. Zhu, et al., Advanced Materials, 29, 1603895 (2017). [3] J. Kang, et al., Advanced Materials, 30, 1802990 (2018). [4] G. Hu, et al., Chem. Soc. Rev., 47, 3265 (2018). [5] J. Kang, et al., Accounts of Chemical Research, 50, 943 (2017). [6] M. Geier, et al., Nature Nanotechnology, 10, 944 (2015). [7] K.-S. Chen, et al., Nano Letters, 17, 2539 (2017). [8] J. Kang, et al., Nano Letters, 16, 7216 (2016). [9] V. K. Sangwan, et al., Nano Letters, 18, 1421 (2018). [10] D. Jariwala, et al., Nano Letters, 16, 497 (2016). [11] V. K. Sangwan, et al., Nature Nanotechnology, 10, 403 (2015). [12] V. K. Sangwan, et al., Nature, 554, 500 (2018). [13] S. B. Homan, et al., Nano Letters, 17, 164 (2017). [14] X. Liu, et al., Advanced Materials, 30, 1801586 (2018).