MRS Meetings and Events


EQ06.06.02 2022 MRS Fall Meeting

Continuous Liquid Metal Printing of High Mobility 2D Oxide Heterostructure Transistors

When and Where

Nov 30, 2022
9:00am - 9:15am

Sheraton, 2nd Floor, Back Bay B



Andrew Hamlin1,Simon Agnew1,Anand Tiwari1,William Scheideler1

Dartmouth College1


Andrew Hamlin1,Simon Agnew1,Anand Tiwari1,William Scheideler1

Dartmouth College1
We introduce a new roller-based Continuous Liquid Metal Printing (CLMP) process for low-temperature, in-air deposition of 2D metal oxides, including InO<sub>x</sub> and GaO<sub>x</sub>. Our R2R compatible printing method uses Van der Waals forces to transfer high-quality, large area (&gt; 30 cm<sup>2</sup>) 3.5 nm conductive oxide films generated by a self-limiting Cabrera-Mott oxidization mechanism in &lt; 3s. We apply the CLMP method to fabricate InO<sub>x</sub> / GaO<sub>x</sub> heterostructure thin film transistors (TFTs) at a maximum process temperature of 200 °C. The CLMP 2D GaO<sub>x</sub> layers were designed to provide a modulation doping effect at the back-channel of the 2D InO<sub>x</sub>, enhancing the free carrier concentration as well as the electronic mobility. The nature of this InO<sub>x</sub> / GaO<sub>x</sub> heterointerface was further investigated by AFM, Kelvin probe measurements, photoelectronic spectroscopy in air (PESA), and Raman spectroscopy. XRD and TEM characterization reveal that the 2D GaO<sub>x</sub> layer is amorphous as deposited, while the 2D InO<sub>x</sub> exhibits large, plate-like grains, an electronically advantageous unique property of CLMP InO<sub>x</sub>. An average linear mobility improvement from µ<sub>0</sub> = 12.5 cm<sup>2</sup>/Vs to µ<sub>0</sub> = 17.5 cm<sup>2</sup>/Vs is observed in comparing pure InO<sub>x</sub> channels with InO<sub>x</sub> / GaO<sub>x</sub> heterostructure TFTs. These heterostructure devices exhibit accumulation mode operation and an average I<sub>on</sub>/I<sub>off</sub> of 10<sup>7</sup>. In summary, our work utilizes a breakthrough high-speed Van der Waals printing to fabricate semiconducting 2D oxide heterostructures for applications to displays, photodetectors, and flexible inorganic electronics.


2D materials

Symposium Organizers

Xu Zhang, Carnegie Mellon University
Monica Allen, University of California, San Diego
Ming-Yang Li, TSMC
Doron Naveh, Bar-Ilan Univ

Publishing Alliance

MRS publishes with Springer Nature