Epitaxial growth of structure-tunable ZnO/ZnS core/shell nanowire arrays using HfO2 as the buffer layer. Issue 20 (4th May 2022)

• Record Type: Journal Article
• Authors: Ru, Fan; Xia, Jing; Li, Xuanze; Liu, Pei; Qiao, Peiyu; Li, Yuye; Cao, Jianyu; Tian, Lifeng; Zhang, Wenjun; Meng, Xiang-Min
• Is Part Of: Nanoscale. Volume 14:Issue 20(2022)
• Page Start: 7579
• Page End: 7588
• Publication Date: 2022-05-04
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/d2nr01560a
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : A two-step thermal deposition method is developed to synthesize structure-tunable and single-crystalline ZnO/ZnS core/shell nanowire arrays using HfO2 as buffer layer, which can promote fabricating high-quality heterostructure based nanodevices. Abstract : Synthesis of high-quality ZnO/ZnS heterostructures with tunable phase and controlled structures is in high demand due to their adjustable band gap and efficient electron–hole pair separation. In this report, for the first time, remote heteroepitaxy of single-crystalline ZnO/ZnS core/shell nanowire arrays has been realized using amorphous HfO2 as the buffer layer. Zinc blende or wurtzite ZnS epilayer can be efficiently fabricated under the same thermal deposition condition by adjusting the buffer layer thickness, even among the same batch of products, respectively. Structural characterization reveals "(01−10)ZnOwz //(2−20)ZnSZB, [0001]ZnOWZ //[001]ZnSZB " and "(01−10)ZnOWZ //(01−10)ZnSWZ, [0002]ZnOWZ //[0002]ZnSWZ " epitaxial relationships between the core and the shell, respectively. The cathodoluminescence measurement demonstrates that the tuning of the optical properties can be accomplished by preparing a heterostructure with HfO2, in which a strong green emission increases at the expense of the quenching of UV emission. In addition, the core/shell heterostructure based Schottky diode exhibits an asymmetrical rectifying behavior and an outstanding photo-electronic switching-effect. We believe that the aforementioned results could provide fundamental insights for epitaxial growth of structure-tunable ZnO/ZnS heterostructures on the nanoscale. Furthermore, this promising route buffered by the high-k material can broaden the options for fabricating heterojunctions and promote their application in photoelectric nanodevices.