Results in Physics ( IF 4.4 ) Pub Date : 2021-09-20 , DOI: 10.1016/j.rinp.2021.104827 Hua Zhou 1 , Hui-Qiong Wang 2, 3 , Jin-Cheng Zheng 2 , Xiao-Dan Wang 2 , Yufeng Zhang 2 , Junyong Kang 2 , Lihua Zhang 4 , Kim Kisslinger 4 , Rui Wu 5 , Jia-Ou Wang 5 , Hai-Jie Qian 5 , Kurash Ibrahim 5
The SrTiO3(STO)/ZnO heterointerface, which is widely used in the fabrication of novel optoelectronic devices, is a classical system combining functional perovskite oxides and wurtzite-structure semiconductor materials. The electronic structure of the heterointerface often plays a significant role in controlling the functions of novel devices. In this study, the electronic structure was explored using in situ photoemission spectroscopy and X-ray absorption spectroscopy. X-ray diffraction results showed the coexistence of (1 1 1)STO and (0 1 1)STO orientations for the STO film deposited on the ZnO-(000 substrate via pulsed laser deposition. High-resolution transmission electron microscopic results revealed two types of polar interfaces: [11][10](1 1 1)STO//[110][100](000)ZnO and [1 1 1][2](0 1 1)STO//[10][100](000)ZnO. In situ photoemission spectroscopic results revealed downward band bending and the transformation of the valence states of Ti from 4+ to 3+, with extra electrons transferring to the hybridization states between O 2p and Ti t2g orbitals at the polar-to-polar STO/ZnO interface. We propose that the polar discontinuity drives the electron transfer to the STO/ZnO interface during the growth process. This study provides insight into the electronic structure of the STO/(000)ZnO heterointerface.
中文翻译:
SrTiO3/(000 1‾ )ZnO异质界面电子结构的原位研究
SrTiO 3 (STO)/ZnO异质界面广泛用于制造新型光电器件,是结合功能性钙钛矿氧化物和纤锌矿结构半导体材料的经典系统。异质界面的电子结构通常在控制新型器件的功能方面起着重要作用。在这项研究中,使用原位光电发射光谱和 X 射线吸收光谱探索了电子结构。X射线衍射结果表明(1并存 1 1)STO和(0 1 1)STO(取向为沉积在ZnO-的STO膜000衬底通过脉冲激光沉积。高分辨率透射电子显微镜结果揭示了两种类型的极性界面:[11][10](1 1 1) STO //[110][100](000)氧化锌和 [1 1 1][2](0 1 1) STO //[10][100](000)氧化锌。原位光电发射光谱结果揭示了向下的带弯曲和 Ti 的价态从 4+ 到 3+ 的转变,额外的电子转移到 O 2p 和 Ti t 2g轨道之间的杂化态在极地到极地 STO/氧化锌界面。我们建议在生长过程中极性不连续性驱动电子转移到 STO/ZnO 界面。这项研究提供了对 STO/(000)ZnO 异质界面。