Du Yuanmin, Peng Hai Yang, Mao Hongying, Jin Ke Xin, Wang Hong, Li Feng, Gao Xing Yu, Chen Wei, Wu Tom
†Materials Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
‡, Advanced LSI Technology Laboratory, Corporate Research and Development Center, Toshiba Corporation, Kawasaki 212-8582, Japan.
ACS Appl Mater Interfaces. 2015 Jun 3;7(21):11309-14. doi: 10.1021/acsami.5b01698. Epub 2015 May 21.
Modifying the surface energetics, particularly the work function of advanced materials, is of critical importance for a wide range of surface- and interface-based devices. In this work, using in situ photoelectron spectroscopy, we investigated the evolution of electronic structure at the SrTiO3 surface during the growth of ultra-thin MoO3 layers. Because of the large work function difference between SrTiO3 and MoO3, the energy band alignment on the SrTiO3 surface is significantly modified. The charge transfer and dipole formation at the SrTiO3-MoO3 interface leads to a large modulation of work function and to apparent doping in SrTiO3. The measured evolutions of electronic structure and upward band bending suggest that the growth of ultra-thin MoO3 layers is a powerful tool with which to modulate the surface energetics of SrTiO3, and this surface engineering approach could be generalized to other functional oxides.
改变表面能，特别是先进材料的功函数，对于广泛的基于表面和界面的器件至关重要。在这项工作中，我们使用原位光电子能谱研究了超薄MoO3层生长过程中SrTiO3表面电子结构的演变。由于SrTiO3和MoO3之间存在较大的功函数差异，SrTiO3表面的能带排列被显著改变。SrTiO3-MoO3界面处的电荷转移和偶极子形成导致功函数的大幅调制以及SrTiO3中明显的掺杂。所测得的电子结构演变和能带向上弯曲表明，超薄MoO3层的生长是调节SrTiO3表面能的有力工具，并且这种表面工程方法可以推广到其他功能氧化物。
