Megasonically Exfoliated Two-Dimensional Nanomaterial Inks NU 2022-071
INVENTORS Lidia Kuo Sonal V. Rangnekar Vinod K. Sangwan Mark C. Hersam*
SHORT DESCRIPTION A new method of processing nanomaterial inks utilizing megasonic exfoliation
BACKGROUND Two-dimensional (2D) materials, a class of nanomaterials, have layer-dependent properties. In 2D matierals, optical and electronic properties can be modulated as a function of thickness. Solution-processing is a method used to exfoliate 2D materials of varying thickness and size that are then utilized in printable electronic inks. However, these nanosheets require low-yield centrifugal separation to isolate the thinnest materials.
ABSTRACT Researchers at Northwestern University have developed a novel technique utilizing sonication at megahertz frequencies to increase the fraction of large-area (>1µm length) monolayer nanosheets from exfoliated MoS2. The resulting MoS2 ink is then aerosol jet-printed onto printed graphene electrodes to create photodetectors. The MoS2 ink has highly ordered thin-film morphology, imporving photogenerated charge transport. This megasonic exfoliation method paired with aerosol jet printing allows the superior optoelctronic properties of ultrathin MoS2 nanosheets to be used in the scalable additive manufacturing of mechanically flexible optoelectronics, with responsivities exceeding 103 A/W, outperforming previously reported all-printed visible photodectors by over 3 orders of magnitude.
APPLICATIONS
ADVANTAGES
PUBLICATION Kuo L, Sangwan VK, Rangnekar SV, Chu TC, Lam D, Zhu Z, Richter LJ, Li R, Szydłowska BM, Downing JR, Luijten BJ, Lauhon LJ, Hersam MC. (2022). All-Printed Ultrahigh-Responsivity MoS2 Nanosheet Photodetectors Enabled by Megasonic Exfoliation. Adv Mater. 34:e2203772.
IP STATUS A provisional patent application has been filed. Aerosolization via megasonic atomization increases the fraction of large-area monolayer nanosheets.