Large Area Ultrathin InN and Tin Doped InN Nanosheets Featuring 2D Electron Gases

Nitu Syed; Alastair Stacey; Ali Zavabeti; Chung Kim Nguyen; Benedikt Haas; Christoph T Koch; Daniel L Creedon; Enrico Della Gaspera; Philipp Reineck; Azmira Jannat; Matthias Wurdack; Sarah E Bamford; Paul J Pigram; Sherif Abdulkader Tawfik; Salvy P Russo; Billy J Murdoch; Kourosh Kalantar-Zadeh; Chris F McConville; Torben Daeneke

doi:10.1021/acsnano.1c09636

Large Area Ultrathin InN and Tin Doped InN Nanosheets Featuring 2D Electron Gases

ACS Nano. 2022 Apr 26;16(4):5476-5486. doi: 10.1021/acsnano.1c09636. Epub 2022 Apr 4.

Authors

Nitu Syed^{1

2}, Alastair Stacey^{2

3}, Ali Zavabeti⁴, Chung Kim Nguyen¹, Benedikt Haas⁵, Christoph T Koch⁵, Daniel L Creedon², Enrico Della Gaspera³, Philipp Reineck⁶, Azmira Jannat⁷, Matthias Wurdack⁸, Sarah E Bamford⁹, Paul J Pigram⁹, Sherif Abdulkader Tawfik^{10

11}, Salvy P Russo^{3

10}, Billy J Murdoch¹², Kourosh Kalantar-Zadeh¹³, Chris F McConville^{3

11}, Torben Daeneke¹

Affiliations

¹ School of Engineering, RMIT University, Melbourne, VIC 3001, Australia.
² School of Physics, The University of Melbourne, Parkville, VIC 3010, Australia.
³ School of Science, RMIT University, Melbourne, VIC 3001, Australia.
⁴ Department of Chemical Engineering, The University of Melbourne, Parkville, VIC 3010, Australia.
⁵ Department of Physics & IRIS Adlershof, Humboldt-Universität zu Berlin, 10099 Berlin, Germany.
⁶ ARC Centre of Excellence for Nanoscale BioPhotonics, School of Science, RMIT University, Melbourne, VIC 3001, Australia.
⁷ Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia.
⁸ ARC Centre of Excellence in Future Low-Energy Electronics Technologies and Department of Quantum Science and Technology, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia.
⁹ Centre for Materials and Surface Science and Department of Mathematical and Physical Sciences, La Trobe University, Melbourne, VIC 3086, Australia.
¹⁰ ARC Centre of Excellence in Exciton Science, School of Science, RMIT University, Melbourne, VIC 3001 Australia.
¹¹ Institute for Frontier Materials, Deakin University, Geelong, VIC 3216, Australia.
¹² RMIT Microscopy and Microanalysis Facility, STEM College, RMIT University, Melbourne, VIC 3001, Australia.
¹³ School of Chemical Engineering, University of New South Wales (UNSW), Kensington, NSW 2031, Australia.

PMID: 35377615
DOI: 10.1021/acsnano.1c09636

Abstract

Indium nitride (InN) has been of significant interest for creating and studying two-dimensional electron gases (2DEG). Herein we demonstrate the formation of 2DEGs in ultrathin doped and undoped 2D InN nanosheets featuring high carrier mobilities at room temperature. The synthesis is carried out via a two-step liquid metal-based printing method followed by a microwave plasma-enhanced nitridation reaction. Ultrathin InN nanosheets with a thickness of ∼2 ± 0.2 nm were isolated over large areas with lateral dimensions exceeding centimeter scale. Room temperature Hall effect measurements reveal carrier mobilities of ∼216 and ∼148 cm² V^-1 s^-1 for undoped and doped InN, respectively. Further analysis suggests the presence of defined quantized states in these ultrathin nitride nanosheets that can be attributed to a 2D electron gas forming due to strong out-of-plane confinement. Overall, the combination of electronic and plasmonic features in undoped and doped ultrathin 2D InN holds promise for creating advanced optoelectronic devices and functional 2D heterostructures.

Keywords: electron gas; indium nitride; liquid-metal printing; plasmon; two-dimensional.