# Creation and Control of Two-Dimensional Electron Gas Using Al-Based Amorphous Oxides/SrTiO$$_3$$ Heterostructures Grown by Atomic Layer Deposition

 Title: Creation and Control of Two-Dimensional Electron Gas Using Al-Based Amorphous Oxides/SrTiO$$_3$$ Heterostructures Grown by Atomic Layer Deposition Author: Lee, Sang Woon; Liu, Yiqun; Heo, Jaeyeong; Gordon, Roy Gerald Note: Order does not necessarily reflect citation order of authors. Citation: Lee, Sang Woon, Yiqun Liu, Jaeyeong Heo and Roy G. Gordon. 2012. Creation and control of two-dimensional electron gas using Al-based amorphous oxides/SrTiO$$_3$$ heterostructures grown by atomic layer deposition. Nano Letters 12(9): 4775-4783. Full Text & Related Files: Lee_CreationControl.pdf (1.573Mb; PDF) Abstract: The formation of a two-dimensional electron gas (2-DEG) using $$SrTiO_3$$ (STO)-based heterostructures provides promising opportunities in oxide electronics. We realized the formation of 2-DEG using several amorphous layers grown by the atomic layer deposition (ALD) technique at 300°C which is a process compatible with mass production and thereby can provide the realization of potential applications. We found that the amorphous $$LaAlO_3$$ (LAO) layer grown by the ALD process can generate 2-DEG $$(\sim 1 × 10^{13}/cm^{2})$$ with an electron mobility of $$4–5 cm^2/V·s$$. A much higher electron mobility was observed at lower temperatures. More remarkably, amorphous $$YAlO_3$$ (YAO) and $$Al_2O_3$$ layers, which are not polar-perovskite-structured oxides, can create 2-DEG as well. 2-DEG was created by means of the important role of trimethylaluminum, $$Me_3Al$$, as a reducing agent for STO during LAO and YAO ALD as well as the $$Al_2O_3$$ ALD process at 300°C. The deposited oxide layer also plays an essential role as a catalyst that enables $$Me_3Al$$ to reduce the STO. The electrons were localized very near to the STO surface, and the source of carriers was explained based on the oxygen vacancies generated in the STO substrate. Published Version: doi:10.1021/nl302214x Other Sources: http://www.chem.harvard.edu/groups/gordon/Create.Control_2D_Electron_Gas_NanoLtrs12,4775-83(2012).pdf Terms of Use: This article is made available under the terms and conditions applicable to Open Access Policy Articles, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#OAP Citable link to this page: http://nrs.harvard.edu/urn-3:HUL.InstRepos:9716627

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Peer reviewed scholarly articles from the Faculty of Arts and Sciences of Harvard University