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DOE OSTI · 1844367

Enhanced tunability of two-dimensional electron gas on SrTiO 3 through heterostructuring

Yoo, Hyang Keun·Moreschini, Luca·Bostwick, Aaron·Walter, Andrew L.·Noh, Tae Won·Rotenberg, Eli·Chang, Young Jun
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Abstract

Two-dimensional electron gases (2DEGs) on the SrTiO 3 (STO) surface or in STO-based heterostructures have exhibited many intriguing phenomena, which are strongly dependent on the 2DEG-carrier density. In this paper, we report that the tunability of the 2DEG-carrier density is significantly enhanced by adding a monolayer LaTiO 3 (LTO) onto the STO. Ultraviolet (UV) irradiation induced maximum carrier density of the 2DEG in LTO/STO is increased by a factor of ~4 times, compared to that of the bare STO. By oxygen gas exposure, it becomes 10 times smaller than that of the bare STO. This enhanced tunability is attributed to the drastic surface property change of a polar LTO layer by UV irradiation and O 2 exposure. This indicates that the 2DEG controllability in LTO/STO is more reliable than that on the bare STO driven by defects, such an oxygen vacancy.

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71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICSPolar oxide interfaceSrTiO3Two-dimensional electron gasUltraviolet patterning

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Yoo, Hyang Keun, Moreschini, Luca, Bostwick, Aaron, Walter, Andrew L., Noh, Tae Won, Rotenberg, Eli, Chang, Young Jun. 2020-09-08. Enhanced tunability of two-dimensional electron gas on SrTiO 3 through heterostructuring. https://doi.org/10.1016/j.cap.2020.08.019

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