Prakash Abhinav, Quackenbush Nicholas F, Yun Hwanhui, Held Jacob, Wang Tianqi, Truttmann Tristan, Ablett James M, Weiland Conan, Lee Tien-Lin, Woicik Joseph C, Mkhoyan K Andre, Jalan Bharat
Department of Chemical Engineering and Materials Science , University of Minnesota , Minneapolis , Minnesota 55414 , United States.
Materials Measurement Science Division, Material Measurement Laboratory , National Institute of Standards and Technology , Gaithersburg , Maryland 20899 , United States.
Nano Lett. 2019 Dec 11;19(12):8920-8927. doi: 10.1021/acs.nanolett.9b03825. Epub 2019 Nov 21.
Separating electrons from their source atoms in La-doped BaSnO, the first perovskite oxide semiconductor to be discovered with high room-temperature electron mobility, remains a subject of great interest for achieving high-mobility electron gas in two dimensions. So far, the vast majority of work in perovskite oxides has focused on heterostructures involving SrTiO as an active layer. Here we report the demonstration of modulation doping in BaSnO as the high room-temperature mobility host without the use of SrTiO. Significantly, we show the use of angle-resolved hard X-ray photoelectron spectroscopy (HAXPES) as a nondestructive approach to not only determine the location of electrons at the buried interface but also to quantify the width of electron distribution in BaSnO. The transport results are in good agreement with the results of self-consistent solution to one-dimensional Poisson and Schrödinger equations. Finally, we discuss viable routes to engineer two-dimensional electron gas density through band-offset engineering.
在镧掺杂的BaSnO₃中，将电子与其源原子分离，这是首个被发现具有高室温电子迁移率的钙钛矿氧化物半导体，对于在二维空间中实现高迁移率电子气而言，仍然是一个备受关注的课题。到目前为止，钙钛矿氧化物领域的绝大多数工作都集中在以SrTiO₃作为活性层的异质结构上。在此，我们报告了在不使用SrTiO₃的情况下，对作为高室温迁移率主体的BaSnO₃进行调制掺杂的演示。重要的是，我们展示了使用角分辨硬X射线光电子能谱（HAXPES）作为一种非破坏性方法，不仅可以确定掩埋界面处电子的位置，还能量化BaSnO₃中电子分布的宽度。输运结果与一维泊松方程和薛定谔方程的自洽解结果吻合良好。最后，我们讨论了通过能带偏移工程来设计二维电子气密度的可行途径。
