Conductivity and band alignment of LaCrO3/SrTiO3 (111) heterostructure

• 来源期刊: 中国物理B（英文版）
• 关键词: oxide heterostructure LaCrO3/SrTiO3 (111) x-ray photoelectron spectroscopy electronic struc-ture
• 年，卷（期）: 2018,（4）
• 页码范围: 401-407
• 页数: 7页
• 语种: 英文
• DOI: 10.1088/1674-1056/27/4/047301

摘要

In this work, we investigate the electrical transport property and electronic structure of oxide heterostructure LaCrO3/SrTiO3 (111). The interface grown under relatively low oxygen partial pressure is found to be metallic with a conducting critical thickness of 11 unit cells of LaCrO3. This criticality is also observed by x-ray photoelectron spec-troscopy, in which the Ti3+ signal intensity at the spectrum edge of the Ti-2p3/2 core level increases rapidly when the critical thickness is reached. The variations of the valence band offset and full width at half maximum of the core-level spectrum with LaCrO3 thickness suggest that the built-in fields exist both in LaCrO3 and in SrTiO3. Two possible origins are proposed:the charge transfer from LaCrO3 and the formation of a quantum well in SrTiO3. Our results shed light on the understanding of the doping mechanism at the polar/non-polar oxide interface. Moreover, due to the interesting lattice and spin structure of LCO in the (111) direction, our work provides a basis for further exploring the novel topological quantum phenomena in this system.