Erasable and recreatable two-dimensional electron gas at the heterointerface of SrTiO3 and a water-dissolvable overlayer

Kun Han; Kaige Hu; Xiao Li; Ke Huang; Zhen Huang; Shengwei Zeng; Dongchen Qi; Chen Ye; Jian Yang; Huan Xu; Ariando Ariando; Jiabao Yi; Weiming Lü; Shishen Yan; X Renshaw Wang

doi:10.1126/sciadv.aaw7286

Erasable and recreatable two-dimensional electron gas at the heterointerface of SrTiO₃ and a water-dissolvable overlayer

Sci Adv. 2019 Aug 16;5(8):eaaw7286. doi: 10.1126/sciadv.aaw7286. eCollection 2019 Aug.

Authors

Kun Han¹, Kaige Hu^{2

3}, Xiao Li^{3

4}, Ke Huang¹, Zhen Huang⁵, Shengwei Zeng⁵, Dongchen Qi^{6

7}, Chen Ye¹, Jian Yang¹, Huan Xu⁸, Ariando Ariando⁵, Jiabao Yi⁹, Weiming Lü¹⁰, Shishen Yan¹⁰, X Renshaw Wang^{1

8}

Affiliations

¹ School of Physical and Mathematical Sciences, Nanyang Technological University, 637371 Singapore, Singapore.
² School of Physics and Optoelectronic Engineering, Guangdong University of Technology, Guangzhou 510006, China.
³ Department of Physics, University of Texas at Austin, Austin, TX 78712, USA.
⁴ Center for Quantum Transport and Thermal Energy Science, School of Physics and Technology, Nanjing Normal University, Nanjing 210023, China.
⁵ Department of Physics and NUSNNI-Nanocore, National University of Singapore, 117411 Singapore, Singapore.
⁶ ARC Centre of Excellence in Future Low-Energy Electronics Technologies, School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, Queensland 4001, Australia.
⁷ Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia.
⁸ School of Electrical and Electronic Engineering, Nanyang Technological University, 639798 Singapore, Singapore.
⁹ Global Innovative Centre for Advanced Nanomaterials, School of Engineering, The University of Newcastle, Callaghan New South Wales 2308 Australia.
¹⁰ Spintronics Institute, School of Physics and Technology, University of Jinan, Jinan 250022, China.

Abstract

While benefiting greatly from electronics, our society also faces a major problem of electronic waste, which has already caused environmental pollution and adverse human health effects. Therefore, recyclability becomes a must-have feature in future electronics. Here, we demonstrate an erasable and recreatable two-dimensional electron gas (2DEG), which can be easily created and patterned by depositing a water-dissolvable overlayer of amorphous Sr₃Al₂O₆ (a-SAO) on SrTiO₃ (STO) at room temperature. The 2DEG can be repeatedly erased or recreated by depositing the a-SAO or dissolving in water, respectively. Photoluminescence results show that the 2DEG arises from the a-SAO-induced oxygen vacancy. Furthermore, by gradually depleting the 2DEG, a transition of nonlinear to linear Hall effect is observed, demonstrating an unexpected interfacial band structure. The convenience and repeatability in the creation of the water-dissolvable 2DEG with rich physics could potentially contribute to the exploration of next generation electronics, such as environment-friendly or water-soluble electronics.