The effect of fabrication conditions on 2DEGs transport characteristics at amorphous-LaAlO3/KTaO3 interfaces. (31st May 2019)

• Record Type: Journal Article
• Authors: Zhang, Hui; Yan, Xi; Zhang, Jing; Zhang, Jine; Han, Furong; Huang, Hailin; Qi, Shaojin; Shi, Wenxiao; Shen, Baogen; Sun, Jirong
• Is Part Of: Materials research express. Volume 6:Number 8(2019)
• Publication Date: 2019-05-31
• Subjects: oxide film -- two-dimensional electron gas -- fabrication condition -- 5d electrons -- hall mobility -- two-band model; Materials science -- Research -- Periodicals; Materials science -- Periodicals; 620.11
• DOI: 10.1088/2053-1591/ab240a
• Languages: English
• ISSNs: 2053-1591

Abstract

Abstract: Two-dimensional electron gases (2DEGs) formed at the interface between two oxide insulators present a promising platform for the exploration of emergent phenomena. While most of the previous works focused on SrTiO3 -based 2DEGs, here we report on a systematic investigation of the 2DEGs at amorphous-LaAlO3 /KTaO3 (a-LAO/KTO) interfaces, focusing on the effect of fabrication conditions on 2DEGs. We found that 2DEGs can be formed in a wide temperature range from room temperature to 750° under the oxygen pressure 1 × 10 –4 Pa. Unexpectedly, its performance shows a unusual strong dependence on fabrication temperature: the Hall mobility increases rapidly with the decrease of substrate temperature. The highest extracted mobility of charge carriers coming from d XZ / d YZ subband is ∼6.6 × 10 3 cm 2 V −1 s −1, achieved under the condition of T S = 100 °C and P O2 = 3 × 10 –5 Pa. This value is higher than that of the 2DEGs of a-LAO/SrTiO3 by a factor of 30, which reveals the unique character of the 2DEGs formed by 5 d electrons. Two-band model is applied for the analysis of the transport behavior, from which information on carrier density and Hall mobility and their dependence on fabrication conditions are determined.