In:
Nanoscale, Royal Society of Chemistry (RSC), Vol. 13, No. 26 ( 2021), p. 11525-11533
Abstract:
II–VI semiconductor heterojunctions show huge potential for application in nanodevice fabrication due to their type-II alignments owing to the better spatial separation of electrons and holes. However, the hetero-epitaxial growth of high-quality heterostructures is still a challenge, especially for materials with large lattice mismatch. In this work, well-aligned single-crystalline ZnO/ZnS core/shell nanorod arrays were obtained by introducing an Al 2 O 3 buffer layer. It is interesting that the nature of the ZnS layer varies with the thickness of the Al 2 O 3 layer. When Al 2 O 3 is less than 2 nm, the interaction between the substrate and epilayer is strong enough to penetrate through the buffer layer, enabling the growth of ZnS on Al 2 O 3 -coated ZnO nanorod arrays. On the basis of detailed characterization, a rational growth mechanism of the core/shell heterostructure is proposed, in which the Al 2 O 3 interlayer can eliminate voids due to the Kirkendall effect around the interface and accommodate a misfit dislocation between the inner ZnO and outer ZnS, resulting in more sufficient strain relaxation in the epitaxy. In addition, cathodoluminescence measurements demonstrate that the optical properties of the ZnO/ZnS heterostructure could be effectively improved by taking advantage of the thin Al 2 O 3 . The I – V curves characterized by PeakForce tunneling atomic force microscopy reveal that the heterostructure shows a typical rectifying behavior and good photoresponse to ultraviolet light. These findings may provide a reasonable and effective strategy for the growth of highly lattice-mismatched heterostructure arrays buffered by the Al 2 O 3 layer, broadening the options for fabricating heterojunctions and promoting their applications in optoelectronic devices.
Type of Medium:
Online Resource
ISSN:
2040-3364
,
2040-3372
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2021
detail.hit.zdb_id:
2515664-0
detail.hit.zdb_id:
2578181-9
