Abstract
Emerging phenomena discovered at the interface between two adjacent layers, such as two-dimensional electron gas (2DEG) and spin–orbit coupling (SOC) provides promising building blocks for future novel electronics. To exploit these phenomena, it is necessary to modulate and harness them via electric, magnetic, and optical stimuli. This study presents an emergent two-dimensional electron gas at the interface between amorphous aluminium nitride (a-AlN) and single crystal strontium titanate (SrTiO3), i.e. the a-AlN/SrTiO3 interface. The amorphous 2DEG system is powerful, controllable, and easily manufactured, demonstrating great potential for nanoelectronics. First, while applying back and top gate, we show that the 2DEG exhibits high mobility and a transition from weak localisation to weak anti-localisation, where weak anti-localisation indicates the appearance of SOC. The carrier mobility and SOC at the 2DEG are highly tunable upon applying gate electric field, which is useful for future oxide electronics. Second, via applying optical stimuli, we modulated the resistance/conductivity of the 2DEG according to key parameters including backgate voltage, wavelength and power of visible-light illumination. We notice an illumination-enhanced gating effect, due to the migration of oxygen vacancies under electrical field and light illumination, and a highly tunable photoconductivity of 2DEG under visible light illumination and electrostatic gating. This work demonstrates the tunability of amorphous two-dimensional electron gas under magnetic, electrical, and optical stimulation, which could pave the way for next-generation electronic devices.
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Acknowledgements
The author thanks Asst. Prof. Wang Xiao, Renshaw, Ye Chen, and Jin Mengjia of the School of Physical and Mathematical Sciences, Nanyang Technological University, for their advice, support, and guidance through this project.
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Wang, J.F. (2021). Transport and Optical Studies of Two-Dimensional Electron Gas in AlN/SrTiO3 Heterostructure. In: Guo, H., Ren, H., Kim, N. (eds) IRC-SET 2020. Springer, Singapore. https://doi.org/10.1007/978-981-15-9472-4_3
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DOI: https://doi.org/10.1007/978-981-15-9472-4_3
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